message stringlengths 2 20.1k | message_type stringclasses 2 values | message_id int64 0 1 | conversation_id int64 1.95k 109k | cluster float64 17 17 | __index_level_0__ int64 3.91k 217k |
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Provide tags and a correct Python 3 solution for this coding contest problem.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4 | instruction | 0 | 85,063 | 17 | 170,126 |
Tags: dp, sortings, two pointers
Correct Solution:
```
n, K = map(int, input().split())
arr = sorted(map(int, input().split()))
freq = {}
for x in arr:
freq[x] = freq.get(x, 0)+1
arr = sorted(freq.keys())
freq = [freq[x] for x in arr]
n = len(arr)
dp = [[0 for _ in range(n+1)] for _ in range(2)]
for k in range(1, K+1):
for i in range(n-1, -1, -1):
j = i
curr = 0
curr_ans = dp[k&1][i+1]
while j < n and abs(arr[i]-arr[j]) <= 5:
curr += freq[j]
curr_ans = max(curr_ans, curr+dp[1-(k&1)][j+1])
j += 1
dp[k&1][i] = curr_ans
print(dp[K&1][0])
``` | output | 1 | 85,063 | 17 | 170,127 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4 | instruction | 0 | 85,064 | 17 | 170,128 |
Tags: dp, sortings, two pointers
Correct Solution:
```
n,k=[int(x) for x in input().split()]
a=[int(x) for x in input().split()]
a.sort()
index={}
for i in range(n):
index[a[i]]=i
dp=[[1]*(k+1) for i in range(n+1)]
for i in range(n+1):
dp[i][0]=0
for i in range(k+1):
dp[0][i]=0
for i in range(1,n+1):
for item in range(5,-1,-1):
if a[i-1]+item in index:
counter=index[a[i-1]+item]-i+1
break
for j in range(k+1):
if i>0:
dp[i][j]=max(dp[i-1][j],dp[i][j])
if j<k:
dp[i+counter][j+1]=max(dp[i+counter][j+1],dp[i-1][j]+counter+1)
print(dp[n][k])
``` | output | 1 | 85,064 | 17 | 170,129 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4 | instruction | 0 | 85,065 | 17 | 170,130 |
Tags: dp, sortings, two pointers
Correct Solution:
```
# Legends Always Come Up with Solution
# Author: Manvir Singh
import os
import sys
from io import BytesIO, IOBase
from math import inf
def main():
n,k=map(int,input().split())
a=sorted(map(int,input().split()))
dp=[[0]*(k+1) for _ in range(n+1)]
l=1
for i in range(1,n+1):
while l<n+1 and a[l-1]-a[i-1]<=5:
for j in range(1,k+1):
dp[l][j]=max(dp[l][j],dp[l-1][j],dp[i-1][j-1]+l-i+1)
l+=1
print(max(max(i) for i in dp))
# region fastio
BUFSIZE = 8192
class FastIO(IOBase):
newlines = 0
def __init__(self, file):
self._fd = file.fileno()
self.buffer = BytesIO()
self.writable = "x" in file.mode or "r" not in file.mode
self.write = self.buffer.write if self.writable else None
def read(self):
while True:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
if not b:
break
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines = 0
return self.buffer.read()
def readline(self):
while self.newlines == 0:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
self.newlines = b.count(b"\n") + (not b)
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines -= 1
return self.buffer.readline()
def flush(self):
if self.writable:
os.write(self._fd, self.buffer.getvalue())
self.buffer.truncate(0), self.buffer.seek(0)
class IOWrapper(IOBase):
def __init__(self, file):
self.buffer = FastIO(file)
self.flush = self.buffer.flush
self.writable = self.buffer.writable
self.write = lambda s: self.buffer.write(s.encode("ascii"))
self.read = lambda: self.buffer.read().decode("ascii")
self.readline = lambda: self.buffer.readline().decode("ascii")
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")
if __name__ == "__main__":
main()
``` | output | 1 | 85,065 | 17 | 170,131 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4
Submitted Solution:
```
n,k=map(int,input().split())
arr=sorted(list(map(int,input().split())))
cnti=[0 for i in range(n)]
for i in range(n):
count=0
for j in range(i,n):
if arr[j] -arr[i] <=5:
count+=1
continue
break
cnti[i] =count
dp=[[0 for i in range(k+1)] for j in range(n+1)]
for i in range(n):
for j in range(k+1):
dp[i+1][j]=max(dp[i+1][j],dp[i][j])
if j<k:
dp[i+cnti[i]][j+1] =max(dp[i+cnti[i]][j+1] ,dp[i][j] +cnti[i])
print(dp[n][k])
``` | instruction | 0 | 85,066 | 17 | 170,132 |
Yes | output | 1 | 85,066 | 17 | 170,133 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4
Submitted Solution:
```
from bisect import bisect_right
import sys
def input():
return sys.stdin.readline().rstrip()
def slv():
n, k = map(int, input().split())
a = list(map(int, input().split()))
a.sort()
dp = [[0]*(k + 1) for i in range(n + 1)]
ans = 0
for ni in range(1, n + 1):
v = a[ni - 1]
cnt = bisect_right(a, v - 6)
for gi in range(1, k + 1):
dp[ni][gi] = dp[cnt][gi - 1] + (ni - cnt)
dp[ni][gi] = max(dp[ni][gi], dp[ni][gi - 1], dp[ni - 1][gi])
ans = max(dp[ni][k] for ni in range(1, n + 1))
print(ans)
return
def main():
t = 1
for i in range(t):
slv()
return
if __name__ == "__main__":
main()
``` | instruction | 0 | 85,067 | 17 | 170,134 |
Yes | output | 1 | 85,067 | 17 | 170,135 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4
Submitted Solution:
```
#DORIME
from sys import stdin
input=stdin.readline
from collections import defaultdict
def f(a,n,k):
cnt=[0]*(n)
a=sorted(a)
for i in range(n):
while i+cnt[i]<n and a[i+cnt[i]]-a[i]<=5: # get shit after the other shit which has absdif (5)
cnt[i]+=1
dp=[[0]*(k+1) for i in range(n+1)]
for i in range(n):
for j in range(k+1):
dp[i+1][j]=max(dp[i+1][j],dp[i][j]) #just random bs
if j+1<=k:
dp[i+cnt[i]][j+1]=max(dp[i+cnt[i]][j+1],dp[i][j]+cnt[i]) # make a team with min value =a[i]
# print(dp)
return (dp[n][k])
n,k=map(int,input().strip().split())
print(f([*map(int,input().strip().split())],n,k))
``` | instruction | 0 | 85,068 | 17 | 170,136 |
Yes | output | 1 | 85,068 | 17 | 170,137 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4
Submitted Solution:
```
from collections import defaultdict
import heapq
import sys
input = sys.stdin.readline
n, k = map(int, input().split())
a = list(map(int, input().split()))
s = set()
cnt = defaultdict(lambda : 0)
for i in a:
cnt[i] += 1
s.add(i)
s = list(s)
s.sort()
ok = []
c, d = [], []
for i in s:
c0, d0 = 0, 0
for j in range(6):
c0 += cnt[i + j]
d0 += min(cnt[i + j], 1)
c.append(c0)
d.append(d0)
m = len(s)
dp = [0] * (m + 1)
for _ in range(k):
dp0 = [0] * (m + 1)
for i in range(m):
j = i + d[i]
if j > m:
break
dp0[j] = max(dp0[j], dp[i] + c[i])
ma = 0
for i in range(m + 1):
ma = max(ma, dp0[i])
dp[i] = ma
if dp[-1] == n:
break
ans = dp[-1]
print(ans)
``` | instruction | 0 | 85,069 | 17 | 170,138 |
Yes | output | 1 | 85,069 | 17 | 170,139 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4
Submitted Solution:
```
from collections import defaultdict
def solve(n, k, nums):
nums.sort()
new_nums = [0]
for i in range(1, n):
x = min(nums[i] - nums[i-1], 6)
new_nums.append(new_nums[-1] + x)
cand_count = new_nums[-1]
candidates = [0] * cand_count
for n in new_nums:
for i in range(n-5, n+1):
if 0 <= i < cand_count:
candidates[i] += 1
prev = [None] * cand_count
max_val = 0
for i in range(cand_count):
max_val = max(max_val, candidates[i])
prev[i] = max_val
#print(candidates)
#print(prev)
for ki in range(1, k):
new = [None] * cand_count
new[0:6] = prev[0:6]
for i in range(6, cand_count):
new[i] = max(new[i-1], prev[i-6]+candidates[i])
prev = new
#print(new)
print(prev[-1])
def solve_from_stdin():
n, k = map(int, input().split())
nums = list(map(int, input().split()))
solve(n, k, nums)
def test():
n, k = 5000, 5000
nums = list(range(0, 5*n, 5))
solve(n, k, nums)
solve_from_stdin()
``` | instruction | 0 | 85,070 | 17 | 170,140 |
No | output | 1 | 85,070 | 17 | 170,141 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4
Submitted Solution:
```
import sys
import math
input = sys.stdin.readline
from functools import cmp_to_key;
def pi():
return(int(input()))
def pl():
return(int(input(), 16))
def ti():
return(list(map(int,input().split())))
def ts():
s = input()
return(list(s[:len(s) - 1]))
def invr():
return(map(int,input().split()))
mod = 998244353;
f = [];
def fact(n,m):
global f;
f = [1 for i in range(n+1)];
f[0] = 1;
for i in range(1,n+1):
f[i] = (f[i-1]*i)%m;
def fast_mod_exp(a,b,m):
res = 1;
while b > 0:
if b & 1:
res = (res*a)%m;
a = (a*a)%m;
b = b >> 1;
return res;
def inverseMod(n,m):
return fast_mod_exp(n,m-2,m);
def ncr(n,r,m):
if r == 0: return 1;
return ((f[n]*inverseMod(f[n-r],m))%m*inverseMod(f[r],m))%m;
def main():
D();
dp = [];
def solve(st,k,n,a):
if st >= n: return 0;
if k <= 0: return 0;
mx = 0;
if dp[k][st] != -1:
return dp[k][st];
for i in range(st,n):
if a[i]-a[st] <= 5:
mx = max(mx,i-st+1+solve(i+1,k-1,n,a));
dp[k][st] = mx;
return mx;
def D():
[n,k] = ti();
a = ti();
a = sorted(a);
global dp;
dp = [[-1 for j in range(n)] for i in range(k+1)];
print(solve(0,k,n,a));
main();
``` | instruction | 0 | 85,071 | 17 | 170,142 |
No | output | 1 | 85,071 | 17 | 170,143 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4
Submitted Solution:
```
n, K = map(int, input().split())
arr = sorted(map(int, input().split()))
freq = {}
for x in arr:
freq[x] = freq.get(x, 0)+1
arr = sorted(freq.keys())
n = len(arr)
dp = [[0 for _ in range(n+1)] for _ in range(2)]
for k in range(1, K+1):
for i in range(n-1, -1, -1):
j = i
ans = dp[k&1][j]
curr = 0
while j < n and abs(arr[i]-arr[j]) <= 5:
curr += freq[arr[i]]
ans = max(ans, curr+dp[1-(k&1)][j+1])
j += 1
dp[k&1][i] = ans
print(max(max(dp[0]), max(dp[1])))
``` | instruction | 0 | 85,072 | 17 | 170,144 |
No | output | 1 | 85,072 | 17 | 170,145 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.
You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).
It is possible that some students not be included in any team at all.
Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
If you are Python programmer, consider using PyPy instead of Python when you submit your code.
Input
The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.
The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.
Output
Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.
Examples
Input
5 2
1 2 15 15 15
Output
5
Input
6 1
36 4 1 25 9 16
Output
2
Input
4 4
1 10 100 1000
Output
4
Submitted Solution:
```
from collections import Counter
from heapq import heapify, heappush, heappop
n,k=map(int,input().split())
a=[int(x ) for x in input().split()]
z=Counter(a)
a=sorted(list(set(a)))
p=[]
for i in range(len(a)):
s=z[a[i]]
c=0
for j in range(1,6):
heappush(p, (-s, i, j ))
if (i-j)>-1:
if a[i]-a[i-j]<=5:
s+=z[a[i-j]]
else:
c=0
break
else:
c=0
break
if c==1:
heappush(p,(-s,i,6))
#print(p)
x=[0]*len(a)
#print(p)
an=0
while k!=0:
#print(p)
xx=heappop(p)
#print(xx,an)
tt=0
for i in range(xx[2]):
tt|=x[xx[1]-i]
if not tt:
for i in range(xx[2]):
x[xx[1]-i]=1
an-=xx[0]
k-=1
if not p:
break
#print(x)
#print(a)
print(an)
``` | instruction | 0 | 85,073 | 17 | 170,146 |
No | output | 1 | 85,073 | 17 | 170,147 |
Provide a correct Python 3 solution for this coding contest problem.
Scores of Final Examination
I am a junior high school teacher. The final examination has just finished, and I have all the students' scores of all the subjects. I want to know the highest total score among the students, but it is not an easy task as the student scores are listed separately for each subject. I would like to ask you, an excellent programmer, to help me by writing a program that finds the total score of a student with the highest total score.
Input
The input consists of multiple datasets, each in the following format.
> n m
> p1,1 p1,2 … p1,n
> p2,1 p2,2 … p2,n
> …
> pm,1 pm,2 … pm,n
>
The first line of a dataset has two integers n and m. n is the number of students (1 ≤ n ≤ 1000). m is the number of subjects (1 ≤ m ≤ 50). Each of the following m lines gives n students' scores of a subject. pj,k is an integer representing the k-th student's score of the subject j (1 ≤ j ≤ m and 1 ≤ k ≤ n). It satisfies 0 ≤ pj,k ≤ 1000.
The end of the input is indicated by a line containing two zeros. The number of datasets does not exceed 100.
Output
For each dataset, output the total score of a student with the highest total score. The total score sk of the student k is defined by sk = p1,k + … + pm,k.
Sample Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output for the Sample Input
105
83
0
Example
Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output
105
83
0 | instruction | 0 | 85,674 | 17 | 171,348 |
"Correct Solution:
```
def main():
n,k = map(int,input().split())
if n * k == 0:
return False
ans = [0 for _ in range(n)]
for _ in range(k):
a = list(map(int,input().split()))
for i in range(n):
ans[i] += a[i]
print(max(ans))
return True
while main():
pass
``` | output | 1 | 85,674 | 17 | 171,349 |
Provide a correct Python 3 solution for this coding contest problem.
Scores of Final Examination
I am a junior high school teacher. The final examination has just finished, and I have all the students' scores of all the subjects. I want to know the highest total score among the students, but it is not an easy task as the student scores are listed separately for each subject. I would like to ask you, an excellent programmer, to help me by writing a program that finds the total score of a student with the highest total score.
Input
The input consists of multiple datasets, each in the following format.
> n m
> p1,1 p1,2 … p1,n
> p2,1 p2,2 … p2,n
> …
> pm,1 pm,2 … pm,n
>
The first line of a dataset has two integers n and m. n is the number of students (1 ≤ n ≤ 1000). m is the number of subjects (1 ≤ m ≤ 50). Each of the following m lines gives n students' scores of a subject. pj,k is an integer representing the k-th student's score of the subject j (1 ≤ j ≤ m and 1 ≤ k ≤ n). It satisfies 0 ≤ pj,k ≤ 1000.
The end of the input is indicated by a line containing two zeros. The number of datasets does not exceed 100.
Output
For each dataset, output the total score of a student with the highest total score. The total score sk of the student k is defined by sk = p1,k + … + pm,k.
Sample Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output for the Sample Input
105
83
0
Example
Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output
105
83
0 | instruction | 0 | 85,675 | 17 | 171,350 |
"Correct Solution:
```
import os,re,sys,operator
from collections import Counter,deque
from operator import itemgetter
from itertools import accumulate,combinations,groupby
from sys import stdin,setrecursionlimit
from copy import deepcopy
import heapq
setrecursionlimit(10**6)
while 1:
n,m=map(int,stdin.readline().rstrip().split())
if (n,m)==(0,0):
break
a=[list(map(int,stdin.readline().rstrip().split())) for _ in range(m)]
print(max(sum(i) for i in zip(*a)))
``` | output | 1 | 85,675 | 17 | 171,351 |
Provide a correct Python 3 solution for this coding contest problem.
Scores of Final Examination
I am a junior high school teacher. The final examination has just finished, and I have all the students' scores of all the subjects. I want to know the highest total score among the students, but it is not an easy task as the student scores are listed separately for each subject. I would like to ask you, an excellent programmer, to help me by writing a program that finds the total score of a student with the highest total score.
Input
The input consists of multiple datasets, each in the following format.
> n m
> p1,1 p1,2 … p1,n
> p2,1 p2,2 … p2,n
> …
> pm,1 pm,2 … pm,n
>
The first line of a dataset has two integers n and m. n is the number of students (1 ≤ n ≤ 1000). m is the number of subjects (1 ≤ m ≤ 50). Each of the following m lines gives n students' scores of a subject. pj,k is an integer representing the k-th student's score of the subject j (1 ≤ j ≤ m and 1 ≤ k ≤ n). It satisfies 0 ≤ pj,k ≤ 1000.
The end of the input is indicated by a line containing two zeros. The number of datasets does not exceed 100.
Output
For each dataset, output the total score of a student with the highest total score. The total score sk of the student k is defined by sk = p1,k + … + pm,k.
Sample Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output for the Sample Input
105
83
0
Example
Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output
105
83
0 | instruction | 0 | 85,676 | 17 | 171,352 |
"Correct Solution:
```
while (True):
a, b = list(map(int, input().split(" ")))
if(a == 0 and b == 0):
break
# print(a, b)
score = [[0] for i in range(b)]
for i in range(b):
score[i] = list(map(int, input().split()))
sum = 0
maxSum = 0
for i in range(a):
sum = 0
for j in range(b):
sum += score[j][i]
if (sum > maxSum):
maxSum = sum
print(maxSum)
``` | output | 1 | 85,676 | 17 | 171,353 |
Provide a correct Python 3 solution for this coding contest problem.
Scores of Final Examination
I am a junior high school teacher. The final examination has just finished, and I have all the students' scores of all the subjects. I want to know the highest total score among the students, but it is not an easy task as the student scores are listed separately for each subject. I would like to ask you, an excellent programmer, to help me by writing a program that finds the total score of a student with the highest total score.
Input
The input consists of multiple datasets, each in the following format.
> n m
> p1,1 p1,2 … p1,n
> p2,1 p2,2 … p2,n
> …
> pm,1 pm,2 … pm,n
>
The first line of a dataset has two integers n and m. n is the number of students (1 ≤ n ≤ 1000). m is the number of subjects (1 ≤ m ≤ 50). Each of the following m lines gives n students' scores of a subject. pj,k is an integer representing the k-th student's score of the subject j (1 ≤ j ≤ m and 1 ≤ k ≤ n). It satisfies 0 ≤ pj,k ≤ 1000.
The end of the input is indicated by a line containing two zeros. The number of datasets does not exceed 100.
Output
For each dataset, output the total score of a student with the highest total score. The total score sk of the student k is defined by sk = p1,k + … + pm,k.
Sample Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output for the Sample Input
105
83
0
Example
Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output
105
83
0 | instruction | 0 | 85,677 | 17 | 171,354 |
"Correct Solution:
```
while True:
n,m=map(int,input().split())
if n==0 and m==0:
break
p=[list(map(int,input().split())) for i in range(m)]
for i in range(1,m):
for j in range(n):
p[i][j]+=p[i-1][j]
print(max(p[m-1]))
``` | output | 1 | 85,677 | 17 | 171,355 |
Provide a correct Python 3 solution for this coding contest problem.
Scores of Final Examination
I am a junior high school teacher. The final examination has just finished, and I have all the students' scores of all the subjects. I want to know the highest total score among the students, but it is not an easy task as the student scores are listed separately for each subject. I would like to ask you, an excellent programmer, to help me by writing a program that finds the total score of a student with the highest total score.
Input
The input consists of multiple datasets, each in the following format.
> n m
> p1,1 p1,2 … p1,n
> p2,1 p2,2 … p2,n
> …
> pm,1 pm,2 … pm,n
>
The first line of a dataset has two integers n and m. n is the number of students (1 ≤ n ≤ 1000). m is the number of subjects (1 ≤ m ≤ 50). Each of the following m lines gives n students' scores of a subject. pj,k is an integer representing the k-th student's score of the subject j (1 ≤ j ≤ m and 1 ≤ k ≤ n). It satisfies 0 ≤ pj,k ≤ 1000.
The end of the input is indicated by a line containing two zeros. The number of datasets does not exceed 100.
Output
For each dataset, output the total score of a student with the highest total score. The total score sk of the student k is defined by sk = p1,k + … + pm,k.
Sample Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output for the Sample Input
105
83
0
Example
Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output
105
83
0 | instruction | 0 | 85,678 | 17 | 171,356 |
"Correct Solution:
```
def main():
import sys
from itertools import chain
while True:
n, m = map(int, sys.stdin.readline().split())
if n == m == 0:
break
A = list(chain.from_iterable(map(int, sys.stdin.readline().split()) for _ in range(m)))
ans = 0
for i in range(n):
sm = sum(A[i::n])
if ans < sm:
ans = sm
print(ans)
if __name__ == '__main__':
main()
``` | output | 1 | 85,678 | 17 | 171,357 |
Provide a correct Python 3 solution for this coding contest problem.
Scores of Final Examination
I am a junior high school teacher. The final examination has just finished, and I have all the students' scores of all the subjects. I want to know the highest total score among the students, but it is not an easy task as the student scores are listed separately for each subject. I would like to ask you, an excellent programmer, to help me by writing a program that finds the total score of a student with the highest total score.
Input
The input consists of multiple datasets, each in the following format.
> n m
> p1,1 p1,2 … p1,n
> p2,1 p2,2 … p2,n
> …
> pm,1 pm,2 … pm,n
>
The first line of a dataset has two integers n and m. n is the number of students (1 ≤ n ≤ 1000). m is the number of subjects (1 ≤ m ≤ 50). Each of the following m lines gives n students' scores of a subject. pj,k is an integer representing the k-th student's score of the subject j (1 ≤ j ≤ m and 1 ≤ k ≤ n). It satisfies 0 ≤ pj,k ≤ 1000.
The end of the input is indicated by a line containing two zeros. The number of datasets does not exceed 100.
Output
For each dataset, output the total score of a student with the highest total score. The total score sk of the student k is defined by sk = p1,k + … + pm,k.
Sample Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output for the Sample Input
105
83
0
Example
Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output
105
83
0 | instruction | 0 | 85,679 | 17 | 171,358 |
"Correct Solution:
```
while True:
n, m = map(int, input().split())
if n == m == 0:
break
students = [0 for _ in range(n)]
for _ in range(m):
scores = list(map(int, input().split()))
for i in range(n):
students[i] += scores[i]
print(max(students))
``` | output | 1 | 85,679 | 17 | 171,359 |
Provide a correct Python 3 solution for this coding contest problem.
Scores of Final Examination
I am a junior high school teacher. The final examination has just finished, and I have all the students' scores of all the subjects. I want to know the highest total score among the students, but it is not an easy task as the student scores are listed separately for each subject. I would like to ask you, an excellent programmer, to help me by writing a program that finds the total score of a student with the highest total score.
Input
The input consists of multiple datasets, each in the following format.
> n m
> p1,1 p1,2 … p1,n
> p2,1 p2,2 … p2,n
> …
> pm,1 pm,2 … pm,n
>
The first line of a dataset has two integers n and m. n is the number of students (1 ≤ n ≤ 1000). m is the number of subjects (1 ≤ m ≤ 50). Each of the following m lines gives n students' scores of a subject. pj,k is an integer representing the k-th student's score of the subject j (1 ≤ j ≤ m and 1 ≤ k ≤ n). It satisfies 0 ≤ pj,k ≤ 1000.
The end of the input is indicated by a line containing two zeros. The number of datasets does not exceed 100.
Output
For each dataset, output the total score of a student with the highest total score. The total score sk of the student k is defined by sk = p1,k + … + pm,k.
Sample Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output for the Sample Input
105
83
0
Example
Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output
105
83
0 | instruction | 0 | 85,680 | 17 | 171,360 |
"Correct Solution:
```
while True :
a = list(map(int,input().split()))
if a[0] == 0:
break
else:
max_sum = 0
s = 0
table = []
for i in range(a[1]):
table.append(list(map(int,input().split())))
for i in range(a[0]):
s = 0
for j in range(a[1]):
s += table[j][i]
max_sum = max(s,max_sum)
print(max_sum)
``` | output | 1 | 85,680 | 17 | 171,361 |
Provide a correct Python 3 solution for this coding contest problem.
Scores of Final Examination
I am a junior high school teacher. The final examination has just finished, and I have all the students' scores of all the subjects. I want to know the highest total score among the students, but it is not an easy task as the student scores are listed separately for each subject. I would like to ask you, an excellent programmer, to help me by writing a program that finds the total score of a student with the highest total score.
Input
The input consists of multiple datasets, each in the following format.
> n m
> p1,1 p1,2 … p1,n
> p2,1 p2,2 … p2,n
> …
> pm,1 pm,2 … pm,n
>
The first line of a dataset has two integers n and m. n is the number of students (1 ≤ n ≤ 1000). m is the number of subjects (1 ≤ m ≤ 50). Each of the following m lines gives n students' scores of a subject. pj,k is an integer representing the k-th student's score of the subject j (1 ≤ j ≤ m and 1 ≤ k ≤ n). It satisfies 0 ≤ pj,k ≤ 1000.
The end of the input is indicated by a line containing two zeros. The number of datasets does not exceed 100.
Output
For each dataset, output the total score of a student with the highest total score. The total score sk of the student k is defined by sk = p1,k + … + pm,k.
Sample Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output for the Sample Input
105
83
0
Example
Input
5 2
10 20 30 40 50
15 25 35 45 55
6 3
10 20 30 15 25 35
21 34 11 52 20 18
31 15 42 10 21 19
4 2
0 0 0 0
0 0 0 0
0 0
Output
105
83
0 | instruction | 0 | 85,681 | 17 | 171,362 |
"Correct Solution:
```
while True:
n,m = map(int, input().split())
if(n+m ==0):
break
li = list()
for i in range(m):
line = [num for num in map(int, input().split())]
li.append(line)
ans = [0 for i in range(n)]
for i in range(m):
for j in range(n):
ans[j] += li[i][j]
print(max(ans))
``` | output | 1 | 85,681 | 17 | 171,363 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5. | instruction | 0 | 86,263 | 17 | 172,526 |
Tags: brute force, greedy
Correct Solution:
```
re = 500000
n = int(input())
ls = list(map(int,input().split()))
my_ls = []
f_ls = []
my_sec = -1
f_sec = -1
for i in ls:
if i <=re:
my_ls.append(i)
elif i>re:
f_ls.append(i)
if my_ls!=[]:
my_sec = max(my_ls) - 1
if f_ls !=[]:
f_sec = 10**6 - min(f_ls)
print(max(my_sec,f_sec))
``` | output | 1 | 86,263 | 17 | 172,527 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5. | instruction | 0 | 86,264 | 17 | 172,528 |
Tags: brute force, greedy
Correct Solution:
```
n = int(input())
a = [int(x) for x in input().strip().split(' ')]
friend = 1000000
me = 0
for i in a:
if i <= 500000:
if i > me:
me = i
else:
if friend > i:
friend = i
ans = me - 1
if ans < 1000000-friend:
ans = 1000000-friend
print(ans)
``` | output | 1 | 86,264 | 17 | 172,529 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5. | instruction | 0 | 86,265 | 17 | 172,530 |
Tags: brute force, greedy
Correct Solution:
```
n = int(input())
a = list(map(int, input().split()))
ans = float("+inf")
for i in range(n+1):
cur = 0
if i:
cur = max(cur, a[i-1]-1)
if i != n:
cur = max(cur, 1000000-a[i])
ans = min(ans, cur)
print(ans)
``` | output | 1 | 86,265 | 17 | 172,531 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5. | instruction | 0 | 86,266 | 17 | 172,532 |
Tags: brute force, greedy
Correct Solution:
```
from bisect import bisect_left, bisect_right
n = int(input())
a = list(map(int, input().split()))
q = 500000
index_left = bisect_left(a, q)
index_right = bisect_right(a, q)
if q in a:
print(499999)
elif len(a) == index_left:
print(a[index_left - 1] - 1)
elif index_right == 0:
print((10 ** 6) - a[index_left])
else:
print(max(a[index_left - 1] - 1, (10 ** 6) - a[index_right]))
``` | output | 1 | 86,266 | 17 | 172,533 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5. | instruction | 0 | 86,267 | 17 | 172,534 |
Tags: brute force, greedy
Correct Solution:
```
n=int(input())
p=list(map(int, input().split()))
t=0
if max(p)<500001:
print(max(p)-1)
else:
p1=[]
for i in p:
if i>500000:
p1.append(10**6-i)
else:
t=i-1
print(max(max(p1),t))
``` | output | 1 | 86,267 | 17 | 172,535 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5. | instruction | 0 | 86,268 | 17 | 172,536 |
Tags: brute force, greedy
Correct Solution:
```
n=int(input())
a=list(map(int,input().split()))
a.sort()
c=0
r=[]
for i in range(n):
r.append(min(a[i]-1,1000000-a[i]))
print(max(r))
``` | output | 1 | 86,268 | 17 | 172,537 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5. | instruction | 0 | 86,269 | 17 | 172,538 |
Tags: brute force, greedy
Correct Solution:
```
import bisect as bs
n, a = int(input()), list(map(int, input().split()))
m = bs.bisect_left(a, 5 * 10 ** 5 + 1)
if m == n:
res = a[m - 1] - 1
elif m == 0:
res = 10 ** 6 - a[0]
else:
res = max(a[m - 1] - 1, 10 ** 6 - a[m])
print(res)
``` | output | 1 | 86,269 | 17 | 172,539 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5. | instruction | 0 | 86,270 | 17 | 172,540 |
Tags: brute force, greedy
Correct Solution:
```
n = int(input())
arr = [int(i) for i in input().split()]
ans = 0
for i in range(n):
ans = max(ans,min(arr[i]-1,1000000-arr[i]))
print(ans)
``` | output | 1 | 86,270 | 17 | 172,541 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5.
Submitted Solution:
```
# number of elements
n = int(input())
# Below line read inputs from user using map() function
positions = list(map(int, input().strip().split()))[:n]
#global variable
me = meVAR = 1
myFrnd = myFrndVAR = 1000000 #10^6
itr = 0
while itr<len(positions):
#print("this is itr : {}".format(itr))
meVAR=positions[itr]-me
myFrndVAR=myFrnd-positions[itr]
if meVAR>myFrndVAR:
break
itr+=1
#print(itr) # the first itr that not follows me<frnd OR itr=len_of_position_list
########################## upper portion done ###################################3
positions[itr:]=reversed(positions[itr:])
#print(positions)
########################## Computing Required Seconds ###############################
minSecondsME=0
minSecondsFrnd=0
for indx, value in enumerate(positions):
#print(indx,value)
if indx<itr:
minSecondsME += (value-me)
me = value
else:
minSecondsFrnd += (myFrnd-value)
myFrnd=value
#print(minSecondsME)
#print(minSecondsFrnd)
result=max(minSecondsME,minSecondsFrnd)
print(result)
``` | instruction | 0 | 86,271 | 17 | 172,542 |
Yes | output | 1 | 86,271 | 17 | 172,543 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5.
Submitted Solution:
```
l1=[]
l2=[]
n=int(input())
l=[int(n) for n in input().split()]
for i in range (0,n):
if l[i]>500000:
l2.append(l[i])
else:
l1.append(l[i])
if len(l1)!=0:
l1.sort()
if len(l2)!=0:
l2.sort()
if len(l1)==0:
print(1000000-l2[0])
elif len(l2)==0:
print(l1[len(l1)-1]-1)
elif l1[len(l1)-1]-1>1000000-l2[0]:
print(l1[len(l1)-1]-1)
else:
print(1000000-l2[0])
``` | instruction | 0 | 86,272 | 17 | 172,544 |
Yes | output | 1 | 86,272 | 17 | 172,545 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5.
Submitted Solution:
```
n = int(input())
li = list(map(int,input().split()))
a = float('inf')
ind = 0
for i in range(n):
if abs(li[i]-500000.5)<a:
ind = i
a = abs(li[i]-500000.5)
if li[ind]<500000.5:
print(li[ind]-1)
else:
print(1000000-li[ind])
``` | instruction | 0 | 86,274 | 17 | 172,548 |
Yes | output | 1 | 86,274 | 17 | 172,549 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5.
Submitted Solution:
```
import sys,math
n = int(input())
a = list(map(int,input().split()))
start = 1
last = 10**6
prize = 0
for i in a:
if (i-start)<(last-i):
prize+=i-start
start = max(start,i)
else:
prize+=(last-i-1)
last = min(last,i)
print(prize)
``` | instruction | 0 | 86,276 | 17 | 172,552 |
No | output | 1 | 86,276 | 17 | 172,553 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5.
Submitted Solution:
```
n=int(input())
ar = list(map(int, input().strip().split(' ')))
lst1=list(filter(lambda x: (x<=500000) , ar))
lst2=list(filter(lambda x: (x>500000) , ar))
lst1.append(1)
lst2.append(1000000)
m=0
for i in range(len(lst1)):
if lst1[i]>m:
m=lst1[i]
mi=min(lst2)
mi=1000000-mi
if mi>m:
print(mi)
else:
print(m)
``` | instruction | 0 | 86,277 | 17 | 172,554 |
No | output | 1 | 86,277 | 17 | 172,555 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You and your friend are participating in a TV show "Run For Your Prize".
At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.
You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.
Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.
What is the minimum number of seconds it will take to pick up all the prizes?
Input
The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.
The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.
Output
Print one integer — the minimum number of seconds it will take to collect all prizes.
Examples
Input
3
2 3 9
Output
8
Input
2
2 999995
Output
5
Note
In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.
In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5.
Submitted Solution:
```
n = int(input())
mas = list(map(int, input().split()))
a = 0
b = 10000000
for el in mas:
if el < 500000:
if el > a:
a = el
else:
if el < b:
b = el
b = 1000000 - b
a = a - 1
if a > b:
print(a)
else:
print(b)
``` | instruction | 0 | 86,278 | 17 | 172,556 |
No | output | 1 | 86,278 | 17 | 172,557 |
Provide a correct Python 3 solution for this coding contest problem.
Step up and down
Kazuki, commonly known as Kerr, who attends JAG University, was invited by your friend this summer to participate in the ICPC (International Collegiate Potchari Contest). ICPC is a sports contest and requires a high degree of athletic ability. However, Mr. Kerr was always in front of the computer, and he was so lacking in exercise that he was tired even if he moved a little. Therefore, Kerr decided to start an easy-to-start exercise, "stepping up and down," as the first step to achieve good results with ICPC.
As the name suggests, stepping up and down is a simple exercise that simply repeats going up and down between the step and the floor. However, in stepping up and down, the effect cannot be obtained unless the feet are raised and lowered correctly. Correct ascent and descent is the movement of the foot that satisfies either of the following two types.
* From the state where both feet are on the floor, the left foot and the right foot are raised on the stepping stone, and both feet are on the stepping stone. Either the left foot or the right foot may be raised first.
* From the state where both feet are on the platform, the left foot and the right foot are lowered to the floor, and both feet are on the floor. Either the left foot or the right foot may be lowered first.
As can be seen from the above, raising and lowering only one leg continuously from the state of being on the floor or stepping stone does not result in correct raising and lowering. In the stepping up / down movement, when any of the above correct up / down movements is satisfied, it is counted as one time, and the larger the count number, the more effective the effect can be obtained. Note that even if you don't go back and forth between the floor and the platform, it counts as one only one way.
You want your teammate, Kerr, to be as strong as possible. So you decided to write a program and check if Kerr was skipping the step up and down. Since the information of the foot that Kerr moved by going up and down the platform is given, find the number of times that he went up and down correctly. However, it is assumed that both feet are on the floor before going up and down the platform.
Input
The input consists of multiple data sets, and the number of data sets contained in one input is 150 or less. The format of each data set is as follows.
> $ n $
> $ f_1 $ $ f_2 $ ... $ f_n $
In the first line, the integer $ n $ ($ 1 \ le n \ le 100 $) representing the number of times the foot is moved is given. In the second line, $ f_i $, which is a character string representing the movement of the foot, is given in chronological order by $ n $, separated by spaces. $ f_i $ is one of the following four types of character strings.
* "lu": Raise your left foot to the platform.
* "ru": Raise your right foot to the platform.
* "ld": Lower your left foot to the floor.
* "rd": Lower your right foot to the floor.
It can be assumed that no action is input that lowers the foot on the floor or raises the foot on the platform.
The line where $ n $ is 0 indicates the end of input. Do not process this data.
Output
For each dataset, output the number of correct steps up and down in one line. Note that if you do not output a line break at the end of each line, or if you output unnecessary characters, it will be judged as an incorrect answer.
Sample Input
Four
lu ru ld rd
Four
lu ld lu ru
1
lu
Ten
ru lu ld rd ru rd ru lu lu rd ld
0
Output for Sample Input
2
1
0
Four
Example
Input
4
lu ru ld rd
4
lu ld lu ru
1
lu
10
ru lu ld rd ru rd ru lu rd ld
0
Output
2
1
0
4 | instruction | 0 | 86,525 | 17 | 173,050 |
"Correct Solution:
```
while 1:
n=int(input())
if n==0:break
a=0
s=input().split()
for i in range(0,len(s)-1,2):
s[i]+=s[i+1]
if(('lu' in s[i] and 'ru' in s[i])or('ld' in s[i] and 'rd' in s[i])):a+=1
print(a)
``` | output | 1 | 86,525 | 17 | 173,051 |
Provide a correct Python 3 solution for this coding contest problem.
Step up and down
Kazuki, commonly known as Kerr, who attends JAG University, was invited by your friend this summer to participate in the ICPC (International Collegiate Potchari Contest). ICPC is a sports contest and requires a high degree of athletic ability. However, Mr. Kerr was always in front of the computer, and he was so lacking in exercise that he was tired even if he moved a little. Therefore, Kerr decided to start an easy-to-start exercise, "stepping up and down," as the first step to achieve good results with ICPC.
As the name suggests, stepping up and down is a simple exercise that simply repeats going up and down between the step and the floor. However, in stepping up and down, the effect cannot be obtained unless the feet are raised and lowered correctly. Correct ascent and descent is the movement of the foot that satisfies either of the following two types.
* From the state where both feet are on the floor, the left foot and the right foot are raised on the stepping stone, and both feet are on the stepping stone. Either the left foot or the right foot may be raised first.
* From the state where both feet are on the platform, the left foot and the right foot are lowered to the floor, and both feet are on the floor. Either the left foot or the right foot may be lowered first.
As can be seen from the above, raising and lowering only one leg continuously from the state of being on the floor or stepping stone does not result in correct raising and lowering. In the stepping up / down movement, when any of the above correct up / down movements is satisfied, it is counted as one time, and the larger the count number, the more effective the effect can be obtained. Note that even if you don't go back and forth between the floor and the platform, it counts as one only one way.
You want your teammate, Kerr, to be as strong as possible. So you decided to write a program and check if Kerr was skipping the step up and down. Since the information of the foot that Kerr moved by going up and down the platform is given, find the number of times that he went up and down correctly. However, it is assumed that both feet are on the floor before going up and down the platform.
Input
The input consists of multiple data sets, and the number of data sets contained in one input is 150 or less. The format of each data set is as follows.
> $ n $
> $ f_1 $ $ f_2 $ ... $ f_n $
In the first line, the integer $ n $ ($ 1 \ le n \ le 100 $) representing the number of times the foot is moved is given. In the second line, $ f_i $, which is a character string representing the movement of the foot, is given in chronological order by $ n $, separated by spaces. $ f_i $ is one of the following four types of character strings.
* "lu": Raise your left foot to the platform.
* "ru": Raise your right foot to the platform.
* "ld": Lower your left foot to the floor.
* "rd": Lower your right foot to the floor.
It can be assumed that no action is input that lowers the foot on the floor or raises the foot on the platform.
The line where $ n $ is 0 indicates the end of input. Do not process this data.
Output
For each dataset, output the number of correct steps up and down in one line. Note that if you do not output a line break at the end of each line, or if you output unnecessary characters, it will be judged as an incorrect answer.
Sample Input
Four
lu ru ld rd
Four
lu ld lu ru
1
lu
Ten
ru lu ld rd ru rd ru lu lu rd ld
0
Output for Sample Input
2
1
0
Four
Example
Input
4
lu ru ld rd
4
lu ld lu ru
1
lu
10
ru lu ld rd ru rd ru lu rd ld
0
Output
2
1
0
4 | instruction | 0 | 86,526 | 17 | 173,052 |
"Correct Solution:
```
while True:
n = int(input())
if n==0:
break
f = list(input().split())
cnt = 0
rf = 0
lf = 0
foot = 0
for i in range(n):
if lf==0 and f[i]=="lu":
lf = 1
elif rf==0 and f[i]=="ru":
rf = 1
if foot==0 and lf==1 and rf==1:
cnt += 1
foot = 1
if lf==1 and f[i]=="ld":
lf = 0
elif rf==1 and f[i]=="rd":
rf = 0
if foot==1 and lf==0 and rf==0:
cnt += 1
foot = 0
print(cnt)
``` | output | 1 | 86,526 | 17 | 173,053 |
Provide a correct Python 3 solution for this coding contest problem.
Step up and down
Kazuki, commonly known as Kerr, who attends JAG University, was invited by your friend this summer to participate in the ICPC (International Collegiate Potchari Contest). ICPC is a sports contest and requires a high degree of athletic ability. However, Mr. Kerr was always in front of the computer, and he was so lacking in exercise that he was tired even if he moved a little. Therefore, Kerr decided to start an easy-to-start exercise, "stepping up and down," as the first step to achieve good results with ICPC.
As the name suggests, stepping up and down is a simple exercise that simply repeats going up and down between the step and the floor. However, in stepping up and down, the effect cannot be obtained unless the feet are raised and lowered correctly. Correct ascent and descent is the movement of the foot that satisfies either of the following two types.
* From the state where both feet are on the floor, the left foot and the right foot are raised on the stepping stone, and both feet are on the stepping stone. Either the left foot or the right foot may be raised first.
* From the state where both feet are on the platform, the left foot and the right foot are lowered to the floor, and both feet are on the floor. Either the left foot or the right foot may be lowered first.
As can be seen from the above, raising and lowering only one leg continuously from the state of being on the floor or stepping stone does not result in correct raising and lowering. In the stepping up / down movement, when any of the above correct up / down movements is satisfied, it is counted as one time, and the larger the count number, the more effective the effect can be obtained. Note that even if you don't go back and forth between the floor and the platform, it counts as one only one way.
You want your teammate, Kerr, to be as strong as possible. So you decided to write a program and check if Kerr was skipping the step up and down. Since the information of the foot that Kerr moved by going up and down the platform is given, find the number of times that he went up and down correctly. However, it is assumed that both feet are on the floor before going up and down the platform.
Input
The input consists of multiple data sets, and the number of data sets contained in one input is 150 or less. The format of each data set is as follows.
> $ n $
> $ f_1 $ $ f_2 $ ... $ f_n $
In the first line, the integer $ n $ ($ 1 \ le n \ le 100 $) representing the number of times the foot is moved is given. In the second line, $ f_i $, which is a character string representing the movement of the foot, is given in chronological order by $ n $, separated by spaces. $ f_i $ is one of the following four types of character strings.
* "lu": Raise your left foot to the platform.
* "ru": Raise your right foot to the platform.
* "ld": Lower your left foot to the floor.
* "rd": Lower your right foot to the floor.
It can be assumed that no action is input that lowers the foot on the floor or raises the foot on the platform.
The line where $ n $ is 0 indicates the end of input. Do not process this data.
Output
For each dataset, output the number of correct steps up and down in one line. Note that if you do not output a line break at the end of each line, or if you output unnecessary characters, it will be judged as an incorrect answer.
Sample Input
Four
lu ru ld rd
Four
lu ld lu ru
1
lu
Ten
ru lu ld rd ru rd ru lu lu rd ld
0
Output for Sample Input
2
1
0
Four
Example
Input
4
lu ru ld rd
4
lu ld lu ru
1
lu
10
ru lu ld rd ru rd ru lu rd ld
0
Output
2
1
0
4 | instruction | 0 | 86,527 | 17 | 173,054 |
"Correct Solution:
```
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time,copy,functools
sys.setrecursionlimit(10**7)
inf = 10**3
eps = 1.0 / 10**10
mod = 10**9+7
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()
def pf(s): return print(s, flush=True)
def main():
rr = []
while True:
n = I()
if n == 0:
break
a = LS()
r = 0
for i in range(len(a)//2):
if a[i*2][1] == a[i*2+1][1]:
r += 1
rr.append(r)
return '\n'.join(map(str, rr))
print(main())
``` | output | 1 | 86,527 | 17 | 173,055 |
Provide a correct Python 3 solution for this coding contest problem.
Step up and down
Kazuki, commonly known as Kerr, who attends JAG University, was invited by your friend this summer to participate in the ICPC (International Collegiate Potchari Contest). ICPC is a sports contest and requires a high degree of athletic ability. However, Mr. Kerr was always in front of the computer, and he was so lacking in exercise that he was tired even if he moved a little. Therefore, Kerr decided to start an easy-to-start exercise, "stepping up and down," as the first step to achieve good results with ICPC.
As the name suggests, stepping up and down is a simple exercise that simply repeats going up and down between the step and the floor. However, in stepping up and down, the effect cannot be obtained unless the feet are raised and lowered correctly. Correct ascent and descent is the movement of the foot that satisfies either of the following two types.
* From the state where both feet are on the floor, the left foot and the right foot are raised on the stepping stone, and both feet are on the stepping stone. Either the left foot or the right foot may be raised first.
* From the state where both feet are on the platform, the left foot and the right foot are lowered to the floor, and both feet are on the floor. Either the left foot or the right foot may be lowered first.
As can be seen from the above, raising and lowering only one leg continuously from the state of being on the floor or stepping stone does not result in correct raising and lowering. In the stepping up / down movement, when any of the above correct up / down movements is satisfied, it is counted as one time, and the larger the count number, the more effective the effect can be obtained. Note that even if you don't go back and forth between the floor and the platform, it counts as one only one way.
You want your teammate, Kerr, to be as strong as possible. So you decided to write a program and check if Kerr was skipping the step up and down. Since the information of the foot that Kerr moved by going up and down the platform is given, find the number of times that he went up and down correctly. However, it is assumed that both feet are on the floor before going up and down the platform.
Input
The input consists of multiple data sets, and the number of data sets contained in one input is 150 or less. The format of each data set is as follows.
> $ n $
> $ f_1 $ $ f_2 $ ... $ f_n $
In the first line, the integer $ n $ ($ 1 \ le n \ le 100 $) representing the number of times the foot is moved is given. In the second line, $ f_i $, which is a character string representing the movement of the foot, is given in chronological order by $ n $, separated by spaces. $ f_i $ is one of the following four types of character strings.
* "lu": Raise your left foot to the platform.
* "ru": Raise your right foot to the platform.
* "ld": Lower your left foot to the floor.
* "rd": Lower your right foot to the floor.
It can be assumed that no action is input that lowers the foot on the floor or raises the foot on the platform.
The line where $ n $ is 0 indicates the end of input. Do not process this data.
Output
For each dataset, output the number of correct steps up and down in one line. Note that if you do not output a line break at the end of each line, or if you output unnecessary characters, it will be judged as an incorrect answer.
Sample Input
Four
lu ru ld rd
Four
lu ld lu ru
1
lu
Ten
ru lu ld rd ru rd ru lu lu rd ld
0
Output for Sample Input
2
1
0
Four
Example
Input
4
lu ru ld rd
4
lu ld lu ru
1
lu
10
ru lu ld rd ru rd ru lu rd ld
0
Output
2
1
0
4 | instruction | 0 | 86,528 | 17 | 173,056 |
"Correct Solution:
```
def main():
while True:
n = int(input())
if n == 0:
exit()
f = [s for s in input().split()]
pm = 'd'
cnt = 0
for m in f:
if m[1] == pm:
cnt += 1
pm = m[1]
print(cnt)
if __name__ == '__main__':
main()
``` | output | 1 | 86,528 | 17 | 173,057 |
Provide a correct Python 3 solution for this coding contest problem.
Step up and down
Kazuki, commonly known as Kerr, who attends JAG University, was invited by your friend this summer to participate in the ICPC (International Collegiate Potchari Contest). ICPC is a sports contest and requires a high degree of athletic ability. However, Mr. Kerr was always in front of the computer, and he was so lacking in exercise that he was tired even if he moved a little. Therefore, Kerr decided to start an easy-to-start exercise, "stepping up and down," as the first step to achieve good results with ICPC.
As the name suggests, stepping up and down is a simple exercise that simply repeats going up and down between the step and the floor. However, in stepping up and down, the effect cannot be obtained unless the feet are raised and lowered correctly. Correct ascent and descent is the movement of the foot that satisfies either of the following two types.
* From the state where both feet are on the floor, the left foot and the right foot are raised on the stepping stone, and both feet are on the stepping stone. Either the left foot or the right foot may be raised first.
* From the state where both feet are on the platform, the left foot and the right foot are lowered to the floor, and both feet are on the floor. Either the left foot or the right foot may be lowered first.
As can be seen from the above, raising and lowering only one leg continuously from the state of being on the floor or stepping stone does not result in correct raising and lowering. In the stepping up / down movement, when any of the above correct up / down movements is satisfied, it is counted as one time, and the larger the count number, the more effective the effect can be obtained. Note that even if you don't go back and forth between the floor and the platform, it counts as one only one way.
You want your teammate, Kerr, to be as strong as possible. So you decided to write a program and check if Kerr was skipping the step up and down. Since the information of the foot that Kerr moved by going up and down the platform is given, find the number of times that he went up and down correctly. However, it is assumed that both feet are on the floor before going up and down the platform.
Input
The input consists of multiple data sets, and the number of data sets contained in one input is 150 or less. The format of each data set is as follows.
> $ n $
> $ f_1 $ $ f_2 $ ... $ f_n $
In the first line, the integer $ n $ ($ 1 \ le n \ le 100 $) representing the number of times the foot is moved is given. In the second line, $ f_i $, which is a character string representing the movement of the foot, is given in chronological order by $ n $, separated by spaces. $ f_i $ is one of the following four types of character strings.
* "lu": Raise your left foot to the platform.
* "ru": Raise your right foot to the platform.
* "ld": Lower your left foot to the floor.
* "rd": Lower your right foot to the floor.
It can be assumed that no action is input that lowers the foot on the floor or raises the foot on the platform.
The line where $ n $ is 0 indicates the end of input. Do not process this data.
Output
For each dataset, output the number of correct steps up and down in one line. Note that if you do not output a line break at the end of each line, or if you output unnecessary characters, it will be judged as an incorrect answer.
Sample Input
Four
lu ru ld rd
Four
lu ld lu ru
1
lu
Ten
ru lu ld rd ru rd ru lu lu rd ld
0
Output for Sample Input
2
1
0
Four
Example
Input
4
lu ru ld rd
4
lu ld lu ru
1
lu
10
ru lu ld rd ru rd ru lu rd ld
0
Output
2
1
0
4 | instruction | 0 | 86,529 | 17 | 173,058 |
"Correct Solution:
```
DOWN = 0
UP = 1
MOVE_LIST = ["lu","ru","ld","rd"]
def get_input():
input_data = int(input())
return input_data
def get_data_list():
data_list = input().split()
return data_list
class Manager:
def __init__(self, move_num, record_list):
self.move_num = move_num
self.record_list = record_list
self.count = 0
self.right_status = DOWN
self.left_status = DOWN
self.kazu_status = DOWN
def watach_move(self):
for move in self.record_list:
if move == "lu":
self.left_status = UP
elif move == "ru":
self.right_status = UP
elif move == "ld":
self.left_status = DOWN
else:
self.right_status = DOWN
self.counter()
def counter(self):
if self.left_status == self.right_status != self.kazu_status:
self.kazu_status = self.left_status
self.count += 1
if __name__ == "__main__":
while True:
move_num = get_input()
if move_num == 0:
break
record_list = get_data_list()
manager = Manager(move_num, record_list)
manager.watach_move()
print(manager.count)
``` | output | 1 | 86,529 | 17 | 173,059 |
Provide a correct Python 3 solution for this coding contest problem.
Step up and down
Kazuki, commonly known as Kerr, who attends JAG University, was invited by your friend this summer to participate in the ICPC (International Collegiate Potchari Contest). ICPC is a sports contest and requires a high degree of athletic ability. However, Mr. Kerr was always in front of the computer, and he was so lacking in exercise that he was tired even if he moved a little. Therefore, Kerr decided to start an easy-to-start exercise, "stepping up and down," as the first step to achieve good results with ICPC.
As the name suggests, stepping up and down is a simple exercise that simply repeats going up and down between the step and the floor. However, in stepping up and down, the effect cannot be obtained unless the feet are raised and lowered correctly. Correct ascent and descent is the movement of the foot that satisfies either of the following two types.
* From the state where both feet are on the floor, the left foot and the right foot are raised on the stepping stone, and both feet are on the stepping stone. Either the left foot or the right foot may be raised first.
* From the state where both feet are on the platform, the left foot and the right foot are lowered to the floor, and both feet are on the floor. Either the left foot or the right foot may be lowered first.
As can be seen from the above, raising and lowering only one leg continuously from the state of being on the floor or stepping stone does not result in correct raising and lowering. In the stepping up / down movement, when any of the above correct up / down movements is satisfied, it is counted as one time, and the larger the count number, the more effective the effect can be obtained. Note that even if you don't go back and forth between the floor and the platform, it counts as one only one way.
You want your teammate, Kerr, to be as strong as possible. So you decided to write a program and check if Kerr was skipping the step up and down. Since the information of the foot that Kerr moved by going up and down the platform is given, find the number of times that he went up and down correctly. However, it is assumed that both feet are on the floor before going up and down the platform.
Input
The input consists of multiple data sets, and the number of data sets contained in one input is 150 or less. The format of each data set is as follows.
> $ n $
> $ f_1 $ $ f_2 $ ... $ f_n $
In the first line, the integer $ n $ ($ 1 \ le n \ le 100 $) representing the number of times the foot is moved is given. In the second line, $ f_i $, which is a character string representing the movement of the foot, is given in chronological order by $ n $, separated by spaces. $ f_i $ is one of the following four types of character strings.
* "lu": Raise your left foot to the platform.
* "ru": Raise your right foot to the platform.
* "ld": Lower your left foot to the floor.
* "rd": Lower your right foot to the floor.
It can be assumed that no action is input that lowers the foot on the floor or raises the foot on the platform.
The line where $ n $ is 0 indicates the end of input. Do not process this data.
Output
For each dataset, output the number of correct steps up and down in one line. Note that if you do not output a line break at the end of each line, or if you output unnecessary characters, it will be judged as an incorrect answer.
Sample Input
Four
lu ru ld rd
Four
lu ld lu ru
1
lu
Ten
ru lu ld rd ru rd ru lu lu rd ld
0
Output for Sample Input
2
1
0
Four
Example
Input
4
lu ru ld rd
4
lu ld lu ru
1
lu
10
ru lu ld rd ru rd ru lu rd ld
0
Output
2
1
0
4 | instruction | 0 | 86,530 | 17 | 173,060 |
"Correct Solution:
```
def ll(char, f):
if char == "l":
return not f
return f
def rr(char, f):
if char == "r":
return not f
return f
while True:
N = int(input())
if N == 0:
break
F = list(input().split())
c = 0
lFalg = False
rFalg = False
before = F[0]
lFalg = ll(F[0][0], lFalg)
rFalg = rr(F[0][0], rFalg)
for i in range(1, len(F)):
if not lFalg == rFalg:
if not before[0] == F[i][0]:
c += 1
lFalg = ll(F[i][0], lFalg)
rFalg = rr(F[i][0], rFalg)
before = F[i]
print(int(c))
``` | output | 1 | 86,530 | 17 | 173,061 |
Provide a correct Python 3 solution for this coding contest problem.
Step up and down
Kazuki, commonly known as Kerr, who attends JAG University, was invited by your friend this summer to participate in the ICPC (International Collegiate Potchari Contest). ICPC is a sports contest and requires a high degree of athletic ability. However, Mr. Kerr was always in front of the computer, and he was so lacking in exercise that he was tired even if he moved a little. Therefore, Kerr decided to start an easy-to-start exercise, "stepping up and down," as the first step to achieve good results with ICPC.
As the name suggests, stepping up and down is a simple exercise that simply repeats going up and down between the step and the floor. However, in stepping up and down, the effect cannot be obtained unless the feet are raised and lowered correctly. Correct ascent and descent is the movement of the foot that satisfies either of the following two types.
* From the state where both feet are on the floor, the left foot and the right foot are raised on the stepping stone, and both feet are on the stepping stone. Either the left foot or the right foot may be raised first.
* From the state where both feet are on the platform, the left foot and the right foot are lowered to the floor, and both feet are on the floor. Either the left foot or the right foot may be lowered first.
As can be seen from the above, raising and lowering only one leg continuously from the state of being on the floor or stepping stone does not result in correct raising and lowering. In the stepping up / down movement, when any of the above correct up / down movements is satisfied, it is counted as one time, and the larger the count number, the more effective the effect can be obtained. Note that even if you don't go back and forth between the floor and the platform, it counts as one only one way.
You want your teammate, Kerr, to be as strong as possible. So you decided to write a program and check if Kerr was skipping the step up and down. Since the information of the foot that Kerr moved by going up and down the platform is given, find the number of times that he went up and down correctly. However, it is assumed that both feet are on the floor before going up and down the platform.
Input
The input consists of multiple data sets, and the number of data sets contained in one input is 150 or less. The format of each data set is as follows.
> $ n $
> $ f_1 $ $ f_2 $ ... $ f_n $
In the first line, the integer $ n $ ($ 1 \ le n \ le 100 $) representing the number of times the foot is moved is given. In the second line, $ f_i $, which is a character string representing the movement of the foot, is given in chronological order by $ n $, separated by spaces. $ f_i $ is one of the following four types of character strings.
* "lu": Raise your left foot to the platform.
* "ru": Raise your right foot to the platform.
* "ld": Lower your left foot to the floor.
* "rd": Lower your right foot to the floor.
It can be assumed that no action is input that lowers the foot on the floor or raises the foot on the platform.
The line where $ n $ is 0 indicates the end of input. Do not process this data.
Output
For each dataset, output the number of correct steps up and down in one line. Note that if you do not output a line break at the end of each line, or if you output unnecessary characters, it will be judged as an incorrect answer.
Sample Input
Four
lu ru ld rd
Four
lu ld lu ru
1
lu
Ten
ru lu ld rd ru rd ru lu lu rd ld
0
Output for Sample Input
2
1
0
Four
Example
Input
4
lu ru ld rd
4
lu ld lu ru
1
lu
10
ru lu ld rd ru rd ru lu rd ld
0
Output
2
1
0
4 | instruction | 0 | 86,531 | 17 | 173,062 |
"Correct Solution:
```
while(True):
n = input()
if n == '0': break
line = input()
qs = line.split(" ")
up = 0
down = 0
cnt = 0
for q in qs:
if q == "lu" or q == "ru" :
up += 1
down = 0
else:
down += 1
up = 0
if up==2 or down == 2:
cnt += 1
print(cnt)
``` | output | 1 | 86,531 | 17 | 173,063 |
Provide a correct Python 3 solution for this coding contest problem.
Step up and down
Kazuki, commonly known as Kerr, who attends JAG University, was invited by your friend this summer to participate in the ICPC (International Collegiate Potchari Contest). ICPC is a sports contest and requires a high degree of athletic ability. However, Mr. Kerr was always in front of the computer, and he was so lacking in exercise that he was tired even if he moved a little. Therefore, Kerr decided to start an easy-to-start exercise, "stepping up and down," as the first step to achieve good results with ICPC.
As the name suggests, stepping up and down is a simple exercise that simply repeats going up and down between the step and the floor. However, in stepping up and down, the effect cannot be obtained unless the feet are raised and lowered correctly. Correct ascent and descent is the movement of the foot that satisfies either of the following two types.
* From the state where both feet are on the floor, the left foot and the right foot are raised on the stepping stone, and both feet are on the stepping stone. Either the left foot or the right foot may be raised first.
* From the state where both feet are on the platform, the left foot and the right foot are lowered to the floor, and both feet are on the floor. Either the left foot or the right foot may be lowered first.
As can be seen from the above, raising and lowering only one leg continuously from the state of being on the floor or stepping stone does not result in correct raising and lowering. In the stepping up / down movement, when any of the above correct up / down movements is satisfied, it is counted as one time, and the larger the count number, the more effective the effect can be obtained. Note that even if you don't go back and forth between the floor and the platform, it counts as one only one way.
You want your teammate, Kerr, to be as strong as possible. So you decided to write a program and check if Kerr was skipping the step up and down. Since the information of the foot that Kerr moved by going up and down the platform is given, find the number of times that he went up and down correctly. However, it is assumed that both feet are on the floor before going up and down the platform.
Input
The input consists of multiple data sets, and the number of data sets contained in one input is 150 or less. The format of each data set is as follows.
> $ n $
> $ f_1 $ $ f_2 $ ... $ f_n $
In the first line, the integer $ n $ ($ 1 \ le n \ le 100 $) representing the number of times the foot is moved is given. In the second line, $ f_i $, which is a character string representing the movement of the foot, is given in chronological order by $ n $, separated by spaces. $ f_i $ is one of the following four types of character strings.
* "lu": Raise your left foot to the platform.
* "ru": Raise your right foot to the platform.
* "ld": Lower your left foot to the floor.
* "rd": Lower your right foot to the floor.
It can be assumed that no action is input that lowers the foot on the floor or raises the foot on the platform.
The line where $ n $ is 0 indicates the end of input. Do not process this data.
Output
For each dataset, output the number of correct steps up and down in one line. Note that if you do not output a line break at the end of each line, or if you output unnecessary characters, it will be judged as an incorrect answer.
Sample Input
Four
lu ru ld rd
Four
lu ld lu ru
1
lu
Ten
ru lu ld rd ru rd ru lu lu rd ld
0
Output for Sample Input
2
1
0
Four
Example
Input
4
lu ru ld rd
4
lu ld lu ru
1
lu
10
ru lu ld rd ru rd ru lu rd ld
0
Output
2
1
0
4 | instruction | 0 | 86,532 | 17 | 173,064 |
"Correct Solution:
```
def solve(n):
ops = input().split()
states = [0 for i in range(n + 1)]
ans = 0
for i in range(n):
if ops[i] == "lu": states[i + 1] = states[i] + 1
elif ops[i] == "ru": states[i + 1] = states[i] + 2
elif ops[i] == "ld": states[i + 1] = states[i] - 1
else: states[i + 1] = states[i] - 2
if i >= 1 and (states[i - 1],states[i + 1]) in [(0,3),(3,0)]:
ans += 1
print(ans)
while True:
n = int(input())
if n == 0: break
solve(n)
``` | output | 1 | 86,532 | 17 | 173,065 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day. | instruction | 0 | 87,126 | 17 | 174,252 |
Tags: dp
Correct Solution:
```
import sys
from functools import lru_cache
from collections import defaultdict
possible = {
0: {'r'},
1: {'r', 'c'},
2: {'r', 'g'},
3: {'r', 'c', 'g'}
}
@lru_cache(maxsize=None)
def min_rest(i, prev_action):
if i == len(arr):
return 0
# At least one elem in the arr.
p = possible[arr[i]]
best = float("inf")
for act in p:
if act == 'r':
# Can always rest, no restrictions.
best = min(best, 1 + min_rest(i + 1, 'r'))
elif act != prev_action:
best = min(best, min_rest(i + 1, act))
return best
def iterative(arr):
DP = defaultdict(int)
for i in range(len(arr) - 1, -1, -1):
p = possible[arr[i]]
for prev_act in ('r', 'c', 'g'):
best = float("inf")
for act in p:
if act == 'r':
# Can always rest, no restrictions.
best = min(best, 1 + DP[('r', i + 1)])
elif act != prev_act:
best = min(best, DP[act, i + 1])
DP[(prev_act, i)] = best
return DP[('r', 0)]
if __name__ == "__main__":
mat = []
for e, line in enumerate(sys.stdin.readlines()):
if e == 0:
continue
arr = list(map(int, line.strip().split()))
# print(min_rest(0, 'r'))
print(iterative(arr))
``` | output | 1 | 87,126 | 17 | 174,253 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day. | instruction | 0 | 87,127 | 17 | 174,254 |
Tags: dp
Correct Solution:
```
days = int(input())
lst = list(map(int,input().split()))
rest, gym, cont = [0], [0], [0]
if lst[0] in (1,3):
cont = [1]
if lst[0] in (2,3):
gym = [1]
for i in range(1,days):
rest.append(max(rest[-1],gym[-1],cont[-1]))
if lst[i] == 3:
cont.append(max(rest[-2],gym[-1])+1)
gym.append(max(rest[-2],cont[-2])+1)
elif lst[i] == 1:
cont.append(max(rest[-2],gym[-1])+1)
elif lst[i] == 2:
gym.append(max(rest[-2],cont[-1])+1)
#print(rest,gym,cont)
print(days-max(rest[-1],gym[-1],cont[-1]))
``` | output | 1 | 87,127 | 17 | 174,255 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day. | instruction | 0 | 87,128 | 17 | 174,256 |
Tags: dp
Correct Solution:
```
n = int(input())
a = list(map(int, input().split(' ')))
dp = [[0 for i in range(3)] for _ in range(102)]
for i in range(1, n + 1):
if a[i - 1] == 0:
dp[i][0] = min(dp[i - 1]) + 1
dp[i][1] = dp[i - 1][1] + 1
dp[i][2] = dp[i - 1][2] + 1
elif a[i - 1] == 1:
dp[i][0] = min(dp[i - 1]) + 1
dp[i][1] = min(dp[i - 1][0], dp[i - 1][2])
dp[i][2] = dp[i- 1][2] + 1
elif a[i - 1] == 2:
dp[i][0] = min(dp[i - 1]) + 1
dp[i][1] = dp[i - 1][1] + 1
dp[i][2] = min(dp[i - 1][0], dp[i - 1][1])
elif a[i - 1] == 3:
dp[i][0] = min(dp[i - 1]) + 1
dp[i][2] = min(dp[i - 1][0], dp[i - 1][1])
dp[i][1] = min(dp[i - 1][0], dp[i - 1][2])
print(min(dp[n]))
``` | output | 1 | 87,128 | 17 | 174,257 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day. | instruction | 0 | 87,129 | 17 | 174,258 |
Tags: dp
Correct Solution:
```
a = int(input())
days = [int(x) for x in input().split()]
dp = [[666, 666, 666] for i in range(a)]
if days[0] == 3:
dp[0][0] = 0
dp[0][1] = 0
dp[0][2] = 0
else:
dp[0][0], dp[0][days[0]] = 0, 0
dp[0][0] += 1
for x in range(1, a):
dp[x][0] = min(dp[x - 1][:]) + 1
if days[x] == 3:
dp[x][1] = min(dp[x - 1][0], dp[x - 1][2])
dp[x][2] = min(dp[x - 1][0], dp[x - 1][1])
elif days[x] == 2:
dp[x][2] = min(dp[x - 1][0], dp[x - 1][1])
elif days[x] == 1:
dp[x][1] = min(dp[x - 1][0], dp[x - 1][2])
print(min(dp[a - 1][:]))
``` | output | 1 | 87,129 | 17 | 174,259 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day. | instruction | 0 | 87,130 | 17 | 174,260 |
Tags: dp
Correct Solution:
```
n = int(input())
arr = list(map(lambda x: int(x), input().split(" ")))
dp = [[None] * n for _ in range(3)]
first = arr[0]
dp[0][0] = 1
if first == 1:
dp[1][0] = 0
if first == 2:
dp[2][0] = 0
if first == 3:
dp[1][0] = 0
dp[2][0] = 0
for c in range(1, n):
val = arr[c]
cand = [dp[0][c-1], dp[1][c-1], dp[2][c-1]]
cand = list(filter(lambda x: x != None, cand))
dp[0][c] = 1+min(cand)
if val == 1 or val == 3:
cand = [dp[0][c-1], dp[2][c-1]]
cand = list(filter(lambda x: x != None, cand))
dp[1][c] = min(cand)
if val == 2 or val == 3:
cand = [dp[0][c-1], dp[1][c-1]]
cand = list(filter(lambda x: x != None, cand))
dp[2][c] = min(cand)
cand = [dp[0][-1], dp[1][-1], dp[2][-1]]
#print(dp)
print(min(filter(lambda x: x != None, cand)))
``` | output | 1 | 87,130 | 17 | 174,261 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day. | instruction | 0 | 87,131 | 17 | 174,262 |
Tags: dp
Correct Solution:
```
def get_ints(string):
return list(map(int, string.split()))
def get_input():
n = int(input())
xs = get_ints(input())
return n, xs
def foo(xs, res, last):
# print(xs)
if len(xs) is []:
return res
for i, x in enumerate(xs):
if x == 0:
res += 1
last = 0
elif x == 1 and last == 1:
res += 1
last = 0
elif x == 1:
last = 1
elif x == 2 and last == 2:
res += 1
last = 0
elif x == 2:
last = 2
else:
if last == 1:
last = 2
elif last == 2:
last = 1
elif i < len(xs)-1 and xs[i+1] == 0:
last = 1
else:
return min(foo(xs[i+1:], res, 1), foo(xs[i+1:], res, 2))
return res
def main():
n, xs = get_input()
res = foo(xs, 0, 0)
print(res)
return res
if __name__ == '__main__':
main()
``` | output | 1 | 87,131 | 17 | 174,263 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day. | instruction | 0 | 87,132 | 17 | 174,264 |
Tags: dp
Correct Solution:
```
n = int(input())
a = [int(i) for i in input().split()]
dp = [[0]*(n+1), [0]*(n+1), [0]*(n+1)]
INF = 1e9
for i in range(1, n + 1):
dp[0][i] = min(dp[0][i - 1], dp[1][i - 1], dp[2][i - 1]) + 1
if a[i - 1] == 0:
dp[1][i] = INF
dp[2][i] = INF
elif a[i - 1] == 1:
dp[1][i] = min(dp[0][i - 1], dp[2][i - 1])
dp[2][i] = INF
elif a[i - 1] == 2:
dp[1][i] = INF
dp[2][i] = min(dp[0][i - 1], dp[1][i - 1])
elif a[i - 1] == 3:
dp[1][i] = min(dp[0][i - 1], dp[2][i - 1])
dp[2][i] = min(dp[0][i - 1], dp[1][i - 1])
print(min(dp[0][n], dp[1][n], dp[2][n]))
``` | output | 1 | 87,132 | 17 | 174,265 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day. | instruction | 0 | 87,133 | 17 | 174,266 |
Tags: dp
Correct Solution:
```
n = int(input())
ai = list(map(int,input().split()))
for i in range(n):
if i < n-1:
if ai[i] % 3 != 0 and ai[i] == ai[i+1]:
ai[i+1] = 0
elif ai[i+1] == 3 and ai[i] % 3 != 0:
ai[i+1] = 3 - ai[i]
ai[i] = int(ai[i] > 0)
print(n - sum(ai))
``` | output | 1 | 87,133 | 17 | 174,267 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Vasya has n days of vacations! So he decided to improve his IT skills and do sport. Vasya knows the following information about each of this n days: whether that gym opened and whether a contest was carried out in the Internet on that day. For the i-th day there are four options:
1. on this day the gym is closed and the contest is not carried out;
2. on this day the gym is closed and the contest is carried out;
3. on this day the gym is open and the contest is not carried out;
4. on this day the gym is open and the contest is carried out.
On each of days Vasya can either have a rest or write the contest (if it is carried out on this day), or do sport (if the gym is open on this day).
Find the minimum number of days on which Vasya will have a rest (it means, he will not do sport and write the contest at the same time). The only limitation that Vasya has — he does not want to do the same activity on two consecutive days: it means, he will not do sport on two consecutive days, and write the contest on two consecutive days.
Input
The first line contains a positive integer n (1 ≤ n ≤ 100) — the number of days of Vasya's vacations.
The second line contains the sequence of integers a1, a2, ..., an (0 ≤ ai ≤ 3) separated by space, where:
* ai equals 0, if on the i-th day of vacations the gym is closed and the contest is not carried out;
* ai equals 1, if on the i-th day of vacations the gym is closed, but the contest is carried out;
* ai equals 2, if on the i-th day of vacations the gym is open and the contest is not carried out;
* ai equals 3, if on the i-th day of vacations the gym is open and the contest is carried out.
Output
Print the minimum possible number of days on which Vasya will have a rest. Remember that Vasya refuses:
* to do sport on any two consecutive days,
* to write the contest on any two consecutive days.
Examples
Input
4
1 3 2 0
Output
2
Input
7
1 3 3 2 1 2 3
Output
0
Input
2
2 2
Output
1
Note
In the first test Vasya can write the contest on the day number 1 and do sport on the day number 3. Thus, he will have a rest for only 2 days.
In the second test Vasya should write contests on days number 1, 3, 5 and 7, in other days do sport. Thus, he will not have a rest for a single day.
In the third test Vasya can do sport either on a day number 1 or number 2. He can not do sport in two days, because it will be contrary to the his limitation. Thus, he will have a rest for only one day.
Submitted Solution:
```
import math
n = int(input())
arr = list(map(int,input().split()))
dp = [[float("inf") for _ in range(n+1)] for j in range(3)]
for i in range(3):
dp[i][0] = 0
for idx in range(1,n+1):
# print(f"idx = {idx} day = {arr[idx-1]}")
# print('\n'.join([''.join(['{:4}'.format(item) for item in row])
# for row in dp]))
day = arr[idx-1]
dp[0][idx] = min([dp[0][idx-1],dp[1][idx-1],dp[2][idx-1]])+1
if day == 1 or day ==3:
dp[1][idx] = min(dp[0][idx-1],dp[2][idx-1])
if day == 2 or day == 3:
dp[2][idx] = min(dp[0][idx-1],dp[1][idx-1])
# print("------------------------------------------------")
# print('\n'.join([''.join(['{:4}'.format(item) for item in row])
# for row in dp]))
#print(dp)
ans = float("inf")
for i in range(3):
ans = min(ans,dp[i][n])
print(ans)
``` | instruction | 0 | 87,134 | 17 | 174,268 |
Yes | output | 1 | 87,134 | 17 | 174,269 |
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