solution stringlengths 11 983k | difficulty int64 0 21 | language stringclasses 2
values |
|---|---|---|
#include <bits/stdc++.h>
using namespace std;
int sc(int &x) { return scanf("%d", &x); }
int sc(unsigned int &x) { return scanf("%u", &x); }
int sc(long long &x) { return scanf("%lld", &x); }
int sc(unsigned long long &x) { return scanf("%llu", &x); }
int sc(double &x) { return scanf("%lf", &x); }
int sc(long double &x... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const long long N = 100005;
long long degree[N];
int main() {
long long n, i, v, u;
cin >> n;
for (i = 0; i < n - 1; i++) {
cin >> v >> u;
degree[v]++;
degree[u]++;
}
for (i = 1; i <= n; i++) {
if (degree[i] == 2) {
cout << "NO\n";
;
... | 10 | CPP |
#include <bits/stdc++.h>
const int inff = 0x3f3f3f3f;
const double eqs = 1e-9;
const double E = 2.718281828459;
const double pi = acos(-1.0);
using namespace std;
const int maxn = 1e5 + 5;
int in[maxn];
int main() {
int n, x, y;
cin >> n;
for (int i = 1; i <= n; i++) in[i] = 0;
for (int i = 1; i < n; i++) {
... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 1e5 + 5;
int n;
vector<int> G[MAX_N];
bool ans = true;
int main() {
scanf("%d", &n);
for (int i = 0, t1, t2; i < n - 1; i++) {
scanf("%d%d", &t1, &t2);
G[t1].emplace_back(t2);
G[t2].emplace_back(t1);
}
for (int i = 1; i <= n; i++)
i... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int n;
vector<vector<int> > a;
void Input() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
a.resize(n);
for (int i = 1; i <= n - 1; i++) {
int x, y;
cin >> x >> y;
x--;
y--;
a[x].push_back(y);
a[y].push_back(x);
}
}
void Process() ... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
long long br[200002];
long long n, x, y;
int main() {
cin >> n;
for (long long i = 1; i < n; i++) {
cin >> x >> y;
br[x]++;
br[y]++;
}
for (long long i = 1; i <= n; i++) {
if (br[i] == 2) {
cout << "NO\n";
return 0;
}
}
cout << "Y... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const unsigned long long hash1 = 201326611;
const unsigned long long hash2 = 50331653;
const int N = 200000 + 10;
const int M = 20;
vector<int> g[N];
int n, vis[N];
int main() {
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
cin >> n;
int u, v;
for (int i =... | 10 | CPP |
n = int(input())
l = [0] * n
for i in range(n - 1):
u , v = map(int , input().split())
l[u - 1] += 1
l[v - 1] += 1
for i in l:
if i == 2:
print("NO")
exit()
print("YES")
| 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
vector<long long> adj[200005];
long long c = 0;
bool vis[200005];
vector<long long> lf;
void dfs(long long v) {
if (vis[v]) {
return;
}
vis[v] = true;
if (adj[v].size() == 1) {
c++;
lf.push_back(v);
}
for (auto u : adj[v]) {
dfs(u);
}
}
int mai... | 10 | CPP |
from sys import stdin, stdout, exit
n = int(input())
graph = [[] for i in range(n)]
for i in range(n-1):
u, v = map(int, stdin.readline().split())
graph[u-1].append(v-1)
graph[v-1].append(u-1)
for i in range(n):
if len(graph[i]) == 2:
print("NO")
exit()
print("YES")
| 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
int main() {
int n, u, v;
cin >> n;
vector<vector<int>> g(n);
for (int i = 0; i < n - 1; i++) {
cin >> u >> v;
g[u - 1].push_back(v - 1);
g[v - 1].push_back(u - 1);
}
for (int i = 0; i < n; i++) {
if (g[i].size() == 2) {
cout << "NO";
... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const int MAX = 1e5 + 1;
int d[MAX];
void solve() {
int n;
cin >> n;
for (int i = 1; i < n; ++i) {
int u, v;
cin >> u >> v;
d[u]++;
d[v]++;
}
for (int i = 1; i <= n; ++i) {
if (d[i] == 2) {
cout << "NO\n";
return;
}
}
cout <... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
vector<int> a[100010];
int main() {
int n, m;
scanf("%d", &n);
int x, y;
for (int i = 0; i < n - 1; i++) {
scanf("%d%d", &x, &y);
a[x].push_back(y);
a[y].push_back(x);
}
if (n == 2) {
printf("YES");
return 0;
}
int f = 1;
for (int i = 1... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const int O = 1e6;
const int mod = 1e9 + 7;
const int maxn = 1e6 + 5;
const double PI = acos(-1.0);
const double E = 2.718281828459;
const double eps = 1e-8;
struct dd {
int to, val, next;
} e[maxn];
int head[maxn], cnt = 0;
void add(int u, int... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
vector<long long> vin(long long n) {
vector<long long> a(n);
for (long long i = 0; i < n; i += 1) cin >> a[i];
return a;
}
long long intin() {
long long n;
cin >> n;
return n;
}
char charin() {
char a;
cin >> a;
return a;
}
string strin() {
string s;
c... | 10 | CPP |
from collections import Counter
n = int(input())
x = []
for _ in range(n-1):
x.extend(input().split())
print('NO' if 2 in Counter(x).values() else 'YES')
| 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
long long n;
cin >> n;
vector<vector<long long>> v(n);
for (long long i = 0; i < n - 1; i++) {
long long a, b;
cin >> a >> b;
v[a - 1].push_back(b - 1);
v[b - 1].push_back(a - 1);
}
... | 10 | CPP |
import sys, os
from io import BytesIO, IOBase
from math import floor, gcd, fabs, factorial, fmod, sqrt, inf, log
from collections import defaultdict as dd, deque
from heapq import merge, heapify, heappop, heappush, nsmallest
from bisect import bisect_left as bl, bisect_right as br, bisect
# region fastio
BUFSIZE = 819... | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
long long n, m, x, y, d[100005];
vector<long long> a[100005];
void solve() {
cin >> n;
m = n - 1;
while (m--) {
cin >> x >> y;
a[x].push_back(y);
a[y].push_back(x);
d[x]++, d[y]++;
}
for (__typeof((n + 1)) i = (1); i < (n + 1); i++) {
if (d[i] ... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
long long n, l, r, cnt = 0;
cin >> n;
vector<long long> v[n + 1];
bool ok = true;
for (long long i = 0; i < n - 1; ++i) {
cin >> l >> r;
v[l].push_back(r);
v[r].push_ba... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
vector<int> AL[100005];
int main() {
int n;
scanf("%d", &n);
for (int i = 0; i < n - 1; i++) {
int u, v;
scanf("%d", &u);
scanf("%d", &v);
AL[u].push_back(v);
AL[v].push_back(u);
}
long long int l = 0;
int fl = 0;
for (int i = 1; i <= n; i+... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int g[100010];
int f;
int main() {
int n, i, j, ok = 0, x, y;
scanf("%d", &n);
for (i = 1; i < n; i++) {
scanf("%d%d", &x, &y);
g[x]++;
g[y]++;
}
for (i = 1; i <= n; i++) {
if (g[i] == 1) f++;
if (g[i] == 2) ok = 1;
}
f = (f * (f - 1)) / 2;... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin >> n;
vector<int> adj[n];
int u, v;
for (int i = 0; i < n - 1; i++) {
cin >> u >> v;
u--;
v--;
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int i = 0; i < n; i... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100005;
int n, root, Over;
vector<int> P[MAXN];
int main() {
scanf("%d", &n);
for (int i = 1, u, v; i < n; i++) {
scanf("%d%d", &u, &v);
P[u].push_back(v);
P[v].push_back(u);
}
for (int i = 1; i <= n; i++)
if (P[i].size() == 2) {
... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
long long in[100005];
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
long long n, x, y;
cin >> n;
for (long long i = 0; i < n - 1; i++) {
cin >> x >> y;
in[x]++;
in[y]++;
}
long long cnt = 0;
bool first = 1;
for (long... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int n, u, v, z = 0, f[100001];
int main() {
for (int i = 1; i <= 10000; i++) z++;
for (int i = 1; i <= 100; i++) z--;
cin >> n;
for (int i = 1; i < n; i++) {
cin >> u >> v;
f[u]++;
f[v]++;
}
for (int i = 1; i <= n; i++)
if (f[i] != 1 && f[i] <= 2... | 10 | CPP |
n=int(input())
dic={}
for x in range(n-1):
a,b=list(map(int,input().split()))
if a in dic:
dic[a]+=1
else:
dic[a]=1
if b in dic:
dic[b]+=1
else:
dic[b]=1
flag=5
for it in dic:
if dic[it]==2:
flag=6
break
if flag==6:
print("NO")
else:
print(... | 10 | PYTHON3 |
n = int(input())
deg = [0 for i in range(n+1)]
for i in range(n-1):
a,b = [int(j) for j in input().split(" ")]
deg[a] += 1
deg[b] += 1
ans = "YES"
for i in range(n+1):
if deg[i] == 2:
ans = "NO"
break
print(ans) | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
int n, x, y;
vector<int> g[100010];
int main() {
cin >> n;
for (int i = 0; i < n - 1; i++) {
scanf("%d%d", &x, &y);
g[x].push_back(y);
g[y].push_back(x);
}
for (int i = 1; i <= n; i++) {
if (g[i].size() == 2) {
pu... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
long long int n;
vector<long long int> G[200020];
int main() {
ios::sync_with_stdio(false);
cin >> n;
for (int i = 0; i < n - 1; i++) {
int x, y;
cin >> x >> y;
G[x].push_back(y);
G[y].push_back(x);
}
for (int i = 1; i <= n; i++) {
if (G[i].siz... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int dirx[] = {1, -1, 0, 0}, diry[] = {0, 0, 1, -1};
long long bigmod(long long x, long long p) {
long long res = 1;
while (p) {
if (p & 1) res = (res * x) % 998244353;
x = (x * x) % 998244353;
p >>= 1;
}
return res;
}
int32_t main() {
ios_base::sync_wi... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int g[100005];
int main() {
int n;
memset(g, 0, sizeof(g));
cin >> n;
for (int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
g[u]++;
g[v]++;
}
for (int i = 1; i <= n; i++) {
if (g[i] == 2) {
cout << "NO";
return 0;
}
}
cou... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
;
const double eps = 1e-8;
const int mod = 1e9 + 7;
const int maxn = 3e5 + 5;
const int INF = 0x3f3f3f3f;
const long long INFLL = 0x3f3f3f3f3f3f3f3f;
struct EDGE {
int v, nxt;
} edge[maxn << 1];
int head[maxn], tot;
void add_edge(int u, int v) {
edge[tot].v = v, edge[to... | 10 | CPP |
n = int(input())
neigh = [[] for _ in range(n)]
for i in range(n-1):
u, v = map(int, input().split())
u -= 1
v -= 1
neigh[u].append(v)
neigh[v].append(u)
no = False
for i in range(n):
if len(neigh[i]) == 2:
no = True
if no:
print('NO')
else:
print('YES')
| 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9 + 7;
const int BASE = 1e9 + 7;
const int dx[4] = {-1, 1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
const int N = 1e5 + 1;
vector<int> a[N];
int pa[N], n;
int F[N];
void DFS(int p, int u) {
bool Check = true;
for (__typeof(a[u].begin()) it = a[u].begin(... | 10 | CPP |
import sys
input = lambda: sys.stdin.readline().strip()
n = int(input())
graph = {}
for i in range(1, n+1): graph[i] = []
for i in range(1, n):
a, b = map(int, input().split())
graph[a].append(b)
graph[b].append(a)
for i in range(1, n+1):
if len(graph[i])==2:
print("NO")
break
else: pri... | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
long long power(long long x, long long y, long long p) {
long long res = 1;
x = x % p;
while (y > 0) {
if (y & 1) res = (res * x) % p;
y = y >> 1;
x = (x * x) % p;
}
return res;
}
std::vector<long long> edge[100045];
int main() {
ios_base::sync_with_... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
bool is_prime(long long n) {
for (long long i = 2; i * i <= n; ++i) {
if (n % i == 0) {
return false;
}
}
return true;
}
vector<long long> fact(long long n) {
n = abs(n);
vector<long long> ans;
for (int i = 1; i * i <= n; i++) {
if (n % i == 0)... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int n, a, b;
vector<int> adj[100005];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
for (int i = (int)1; i <= (int)n - 1; i++) {
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
for (int i = (int)1; i <= (i... | 10 | CPP |
n = int(input())
node = []
for i in range(1 + n):
node.append( [] )
for q in range(n - 1):
k = list(map(int, input().split()))
node[ k[0] ].append( k[1] )
node[ k[1] ].append( k[0] )
hobe = True
for i in range(n + 1):
if(len(node[i]) == 2):
hobe = False
if hobe :
print("YES")
else :
print("NO") | 10 | PYTHON3 |
#! /usr/bin/env python3
import sys
from math import factorial
class Node:
def __init__(self, num):
self.num = num
self.binds = []
# for dijkstra
self.marker = False
self.val = None
def add_bind(self, oth):
self.binds.append(oth)
def __repr__(self):
... | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
const long long inff = 0x3f3f3f3f3f3f3f3f;
int n, x, y, du[100008];
int main() {
cin.tie(0);
cout.tie(0);
cin >> n;
for (int i(1); i <= (n - 1); ++i) {
scanf("%d", &x), scanf("%d", &y);
du[x]++, du[y]++;
}
for (int i(1); i <= (n); ++i)
if (du[i] == 2... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int main() {
int n, f = 0;
cin >> n;
vector<int> V[100008];
for (int i = 0; i < n - 1; i++) {
int u, v;
cin >> u >> v;
V[u].push_back(v);
V[v].push_back(u);
}
for (int i = 0; i <= n; i++) {
if (V[i].size() == 2) {
f = 1;
break;
... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int cnt[100005];
int main() {
int n;
scanf("%d", &n);
if (n == 2) {
printf("YES\n");
return 0;
}
if (n == 3) {
printf("NO\n");
return 0;
}
for (int i = 0; i < n - 1; i++) {
int u, v;
scanf("%d%d", &u, &v);
cnt[u]++;
cnt[v]++;
... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> v[101010];
int main() {
scanf("%d", &n);
for (int i = 1; i < n; i++) {
int a, b;
scanf("%d %d", &a, &b);
v[a].push_back(b);
v[b].push_back(a);
}
for (int i = 1; i <= n; i++)
if (v[i].size() == 2) return !printf("NO");
printf(... | 10 | CPP |
n=int(input())
a=[0]*n
for i in range(n-1):
c,d=map(int,input().split())
a[c-1]+=1
a[d-1]+=1
stat=2 in a
if(stat):
print('NO')
else:
print('YES') | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
vector<int> g[100005];
int find(int v, int* parent) {
if (parent[v] == v) {
return v;
}
return find(parent[v], parent);
}
int vis[100005];
int dp[100005];
int dfs(int u) {
vis[u] = 1;
for (int i = 0; i < g[u].size(); i++) {
int v = g[u][i];
if (!vis[v]... | 10 | CPP |
#include <bits/stdc++.h>
int main() {
long long in[100005];
long long n, i, j, m, t;
memset(in, 0, sizeof(in));
scanf("%lld", &n);
for (i = 1; i <= n - 1; i++) {
long long u, v;
scanf("%lld %lld", &u, &v);
in[u]++;
in[v]++;
}
long long num = 0;
long long ans = 0;
int flag = 1;
for (i... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> adj;
int main() {
int n;
cin >> n;
adj = vector<vector<int>>(n + 1);
for (int i = 0; i < n - 1; i++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
string ans = "YES\n";
int flag = 1;
for (int i = 1... | 10 | CPP |
import sys
input = sys.stdin.readline
from collections import deque
class Graph(object):
"""docstring for Graph"""
def __init__(self,n,d): # Number of nodes and d is True if directed
self.n = n
self.graph = [[] for i in range(n)]
self.parent = [-1 for i in range(n)]
self.directed = d
def addEdge(self,x,y... | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
int degree[100005];
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
for (int i = 1; i < n; ++i) {
int u, v;
cin >> u >> v;
++degree[u];
++degree[v];
}
for (int i = 1; i <= n; ++i) {
if (degree[i] == 2) {
cout <<... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const long long max_n = 1e6 + 20;
long long n, m, k, ans, sum;
long long a[max_n];
long long mark[max_n];
vector<long long> v, adj[max_n], jda[max_n];
void dfs(long long v) {
mark[v] = 1;
if (adj[v].size() == 2) ans = -1;
for (auto i : adj[v]) {
if (!mark[i]) {
... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 10;
int n, u, v;
int a[MAXN];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
memset(a, 0, sizeof(a));
for (int i = 0; i < n - 1; i++) {
cin >> u >> v;
a[u]++;
a[v]++;
}
long long cnt[3] = {0, 0, 0};
for (i... | 10 | CPP |
n = int(input())
degree = [0 for i in range(n)]
for i in range(n-1):
a = [int(i) for i in input().split()]
x = a[0]-1
y = a[1]-1
degree[x]+=1
degree[y]+=1
flag = 0
for i in range(n):
if(degree[i] == 2):
flag=1
break
if(flag==0):
print("YES")
else:
print("NO") | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
int n, cnt[100009];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
;
cin >> n;
for (int i = 1; i < n; i++) {
int x, y;
cin >> x >> y;
cnt[x]++, cnt[y]++;
}
for (int i = 1; i <= n; i++)
if (cnt[i] == 2) return cout << "NO"... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const long long maxn = 1e5 + 10;
long long n, deg[maxn];
long long read() {
long long x = 0, f = 1;
char ch = getchar();
while (ch < '0' || ch > '9') {
if (ch == '-') f = -1;
ch = getchar();
}
while (ch >= '0' && ch <= '9') {
x = x * 10 + ch - '0';
... | 10 | CPP |
n=int(input())
ar=[0]*n
for i in range(n-1):
a,b=map(int,input().split())
ar[a-1]+=1
ar[b-1]+=1
ans="YES"
for i in range(n):
if(ar[i]==2):
ans="NO"
break
print(ans) | 10 | PYTHON3 |
import sys
input = sys.stdin.readline
def getN():
return int(input())
def getList():
return list(map(int, input().split()))
from sys import exit
n = getN()
vertex = [[] for i in range(n)]
for i in range(n-1):
a, b = getList()
vertex[a-1].append(b-1)
vertex[b - 1].append(a - 1)
for v in vertex:
... | 10 | PYTHON3 |
n = int(input())
# n, k = map(int, input().split())
# a = [int(i) for i in input().split()]
d = [0 for i in range(n + 1)]
for i in range(n - 1):
a, b = map(int, input().split())
d[a] += 1; d[b] += 1
for val in d:
if val == 2:
print("NO")
exit()
print("YES")
| 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
vector<long long> tree[500500];
long long num[500500], fine = 0, n;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> n;
for (int i = 1; i < n; i++) {
long long u, v;
cin >> u >> v;
tree[u].push_back(v);
tree[v].p... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
void solve() {
int n, u, v;
cin >> n;
vector<int> Adj[n];
for (int i = 1; i < n; ++i) {
cin >> u >> v;
--u;
--v;
Adj[u].push_back(v);
Adj[v].push_back(u);
}
for (int i = 0; i < n; ++i) {
if (Adj[i].size()... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
long long powmod(long long a, long long b) {
long long res = 1;
a %= mod;
assert(b >= 0);
for (; b; b >>= 1) {
if (b & 1) res = res * a % mod;
a = a * a % mod;
}
return res;
}
long long gcd(long long a, long long b) { re... | 10 | CPP |
n = int(input())
adj = [0 for i in range(n)]
for i in range(n-1):
iarr = list(map(int,input().split()))
u = iarr[0]-1
v = iarr[1]-1
adj[u]+=1
adj[v]+=1
flag = 0
for i in adj:
if i==2:
flag=1
break
if flag==1:
print("NO")
else:
print("YES")
| 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
int main() {
int n;
cin >> n;
vector<vector<int>> g(n);
int f, t;
for (int i = 0; i < n - 1; ++i) {
cin >> f >> t;
f--;
t--;
g[f].push_back(t);
g[t].push_back(f);
}
for (int i = 0; i < n; ++i) {
if (g[i].size() == 2) {
cout << "NO... | 10 | CPP |
n=int(input())
d={}
o,t=0,0
for _ in range(n-1):
s,e=map(int,input().split())
if s in d:
d[s]+=1
else:
d[s]=1
if e in d:
d[e]+=1
else:
d[e]=1
for i in d:
if d[i]==1:
o+=1
elif d[i]==2:
t+=1
if t:
print('NO')
else:
if (o*(o-1))//2>=n-1:
... | 10 | PYTHON3 |
from sys import stdin
input = stdin.readline
n = int(input())
degree = [0 for i in range(n+1)]
for _ in range(n-1):
i, j = [int(i) for i in input().split()]
degree[i] += 1
degree[j] += 1
res = False
for i in range(1, n+1):
if degree[i] == 2: res = True
if res: print("NO")
else: print("... | 10 | PYTHON3 |
n=int(input())
tree=[[] for i in range(n)]
for i in range(n-1):
u,v=map(int,input().split())
tree[u-1].append(v-1)
tree[v-1].append(u-1)
if n==2:
print("YES")
exit()
#nが4以上
for i in range(n):
if len(tree[i])==2:
print("NO")
break
else:
print("YES") | 10 | PYTHON3 |
if __name__ == '__main__':
n = int(input())
g = [[] for _ in range(n)]
for _ in range(n - 1):
u, v = map(int, input().split())
g[u - 1].append(v - 1)
g[v - 1].append(u - 1)
if list(filter(lambda x: len(x) == 2, g)):
print("NO")
else:
print("YES") | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 10;
int a[N];
int main() {
int n;
scanf("%d", &n);
for (int i = 1; i < n; i++) {
int x, y;
scanf("%d%d", &x, &y);
a[x]++;
a[y]++;
}
for (int i = 1; i <= n; i++)
if (a[i] == 2) {
printf("NO\n");
return 0;
}
... | 10 | CPP |
n = int(input())
a = []
for i in range(0,n+9):
a.append(0)
for i in range(1,n):
u,v = map(int,input().split())
a[u] = a[u]+1
a[v] = a[v]+1
flag = 1;
for i in range(1,n+1):
if a[i]==2:
flag = 0
if flag==0:
print("NO")
else:
print("YES")
| 10 | PYTHON3 |
from collections import defaultdict
g = defaultdict(set)
n = int(input())
for _ in range(n - 1):
u, v = map(int, input().split())
g[u].add(v)
g[v].add(u)
def solve(n, g):
for i in range(1, n + 1):
if len(g[i]) == 1 or len(g[i]) >= 3:
continue
else:
return Fals... | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5 + 7;
long long n;
vector<long long> add[N];
void nie() {
cout << "NO";
exit(0);
}
void yie() {
cout << "YES";
exit(0);
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
vector<pair<long long, long long>> v;
cin >> n;
... | 10 | CPP |
n = int(input())
l = [0 for i in range(n)]
for _ in range(n-1):
a, b = list(map(int, input().split()))
l[a-1] += 1
l[b-1] += 1
for i in range(n):
if (l[i] == 2):
print('NO')
break
else:
print('YES') | 10 | PYTHON3 |
from collections import Counter
from sys import stdin
n=int(input())
lst=[]
for _ in range(n-1):
a,b=map(int,stdin.readline().split())
lst.append(a)
lst.append(b)
fg=0
for _,i in Counter(lst).items():
if i==2:
fg=1
break
if fg==1:
print("NO")
else:
print("YES") | 10 | PYTHON3 |
#include <bits/stdc++.h>
#pragma GCC optimize("-O2")
using namespace std;
const int LIM = 1e5 + 5, MOD = 1e9 + 7;
const long double EPS = 1e-9;
vector<vector<int> > g;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
g.resize(n);
for (int i = 0; i < n - 1; ++i) {
in... | 10 | CPP |
n = int(input())
edges = [0]*(n+1)
isPossible = True
for i in range(n-1):
a,b = [int(i) for i in input().split()]
edges[a]+=1
edges[b]+=1
for d in edges:
if d == 2:
isPossible = False
break
print("YES" if isPossible else "NO") | 10 | PYTHON3 |
import sys
N = int(input())
adj_list = [[] for _ in range(N)]
for _ in range(N-1):
(u,v) = list(map(int, input().split()))
u -= 1
v -= 1
adj_list[u].append(v)
adj_list[v].append(u)
num_leaf = 0
for node in range(N):
if len(adj_list[node]) == 2:
print("NO")
sys.exit(0)
print("Y... | 10 | PYTHON3 |
from sys import stdin
input=stdin.readline
n=int(input())
a=[[] for i in range(n)]
for i in range(n-1):
c,d=map(int,input().split())
a[c-1].append(d-1)
a[d-1].append(c-1)
if n==2:
print('YES')
else:
k=0
for i in a:
if len(i)==2:
exit(print('NO'))
print('YES')
| 10 | PYTHON3 |
# |
# _` | __ \ _` | __| _ \ __ \ _` | _` |
# ( | | | ( | ( ( | | | ( | ( |
# \__,_| _| _| \__,_| \___| \___/ _| _| \__,_| \__,_|
import sys
import math
def read_line():
return sys.stdin.readline()[:-1]
def read_int():
retu... | 10 | PYTHON3 |
def ii():
return int(input())
def ss():
return [x for x in input()]
def si():
return [int(x) for x in input().split()]
def mi():
return map(int, input().split())
a = ii()
s = [0 for i in range(a)]
for i in range(a - 1):
c, d = [int(x) - 1 for x in input().split()]
s[c] += 1
s[d] += 1
if 2 in s:
print("... | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
void func() {
int n;
cin >> n;
vector<int> adj[n + 1];
for (int i = 0; i < n - 1; i++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
for (int i = 1; i <= n; i++) {
if (adj[i].size() == 1) continue;
if (adj[i].size... | 10 | CPP |
import sys
input=sys.stdin.readline
from collections import deque
n=int(input())
if n==2:
print('YES')
exit()
if n==3:
print('NO')
exit()
Edges=[[] for _ in range(n)]
for _ in range(n-1):
u,v=map(lambda x: int(x)-1,input().split())
Edges[u].append(v)
Edges[v].append(u)
for i,E in enumerate(E... | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
const long long MAX = 1e5 + 10;
long long arr[MAX];
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
for (int i = 0; i < n - 1; i++) {
int u, v;
cin >> u >> v;
arr[u]++;
arr[v]++;
}
for (int i = 1; i <= n; i++)
if... | 10 | CPP |
#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
const int N = 3e5 + 5, M = 1e8 + 5, OO = 1000000;
int T, n, m;
int u, v;
int deg[N];
int main() {
scanf("%d", &n);
for (int i = 1; i < n; ++i) {
scanf("%d %d", &u, &v);
++deg[u], ++deg[v];
}
for (int i = 1; i <= n; ++i) {
if (d... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int a[100010];
int main() {
int n, flag = 1;
scanf("%d", &n);
for (int i = 1, x, y; i < n; i++) {
scanf("%d %d", &x, &y);
a[x]++;
a[y]++;
}
for (int i = 1; i <= n; i++)
if (a[i] == 2) flag = 0;
flag ? printf("YES") : printf("NO");
}
| 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int deg[100005];
int main() {
int n;
scanf("%d", &n);
for (int i = 1; i < n; i++) {
int u, v;
scanf("%d%d", &u, &v);
deg[u]++;
deg[v]++;
}
for (int i = 1; i <= n; i++) {
if (deg[i] == 2) {
printf("NO\n");
return 0;
}
}
print... | 10 | CPP |
n = int(input())
nodes = [[] for _ in range(n)]
edges = []
for _ in range(n-1):
u, v = sorted(map(int, input().split(" ")))
u -= 1
v -= 1
nodes[u].append(v)
nodes[v].append(u)
edge = [u, v]
edges.append(edge)
leaf_nodes = [node for node in nodes if len(node) == 1]
num_ads = [len(node) for... | 10 | PYTHON3 |
from collections import defaultdict
n = int(input())
hash = defaultdict(list)
for i in range(n-1):
a,b = map(int,input().split())
hash[a].append(b)
hash[b].append(a)
flag = 1
for i in hash.keys():
if len(hash[i]) == 2:
flag = 0
break
if flag:
print('YES')
else:
print('NO')
| 10 | PYTHON3 |
#include <bits/stdc++.h>
using ll = int64_t;
using namespace std;
const int N = 1e6 + 5;
int n;
int a[N];
basic_string<int> g[N];
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n;
for (int i = 1, u, v; i < n; i++) {
cin >> u >> v;
g[u] += v;
g[v] += u;
}
for (int i = 1; i <= n; i++) {
... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int n;
int n1, n2;
int grau[100010];
vector<pair<int, int> > edges;
int main() {
scanf("%d", &n);
for (int g = 0; g < n - 1; g++) {
scanf("%d %d", &n1, &n2);
grau[n1]++;
grau[n2]++;
}
for (int g = 1; g <= n; g++) {
if (grau[g] == 2) {
printf("N... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int dx8[] = {1, 1, 0, -1, -1, -1, 0, 1};
int dy8[] = {0, 1, 1, 1, 0, -1, -1, -1};
int dx4[] = {1, 0, -1, 0};
int dy4[] = {0, 1, 0, -1};
template <class A, class B>
ostream& operator<<(ostream& out, const pair<A, B>& a) {
return out << "(" << a.first << "," << a.second << ... | 10 | CPP |
import sys
input = sys.stdin.readline
n = int(input())
a = [list(map(int, input().split())) for i in range(n-1)]
tree = [[] for i in range(n)]
for i in range(n - 1):
tree[a[i][0] - 1].append(a[i][1] - 1)
tree[a[i][1] - 1].append(a[i][0] - 1)
for i in range(n):
if len(tree[i]) == 2:
print("NO")
... | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
int deg[200000];
int main() {
int n;
cin >> n;
for (int i = 0; i < n - 1; ++i) {
int u, v;
cin >> u >> v;
deg[u]++;
deg[v]++;
}
for (int i = 1; i <= n; ++i) {
if (deg[i] == 2) {
cout << "NO\n";
return 0;
}
}
cout << "YES\n";... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
int main() {
int x, y, n;
cin >> n;
vector<int> v[100010], barg;
for (int i = 0; i < n - 1; i++) {
cin >> x >> y;
v[x].push_back(y);
v[y].push_back(x);
}
for (int i = 1; i <= n; i++) {
if (v[i].size() == 2) {
cout << "NO";
return 0;
... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 1000, mod = 1e9 + 7;
vector<int> vec[N];
long long bin_pow(int x, int y) {
if (y == 0) return 1;
if (y == 1) return x;
if (y % 2 == 0) {
long long z = bin_pow(x, y / 2);
return (z * z) % mod;
}
return (bin_pow(x, y - 1) * x) % mod;
}
bo... | 10 | CPP |
#include <bits/stdc++.h>
using namespace std;
vector<vector<long long> > g;
void endProg() {
cout << "NO";
exit(0);
}
void dfs(long long v, long long p) {
long long l = 0;
for (auto i : g[v]) {
if (i == p) continue;
if (g[i].size() == 1) {
l++;
continue;
}
dfs(i, v);
}
if (v == 0... | 10 | CPP |
import sys
num = int(input())
deg = [0]*(num+1)
for _ in range(1,num):
a, b = [int(i) for i in input().split()]
deg[a ] += 1
deg[b] += 1
for i in range(1, num+1):
if deg[i] == 2:
print("NO")
sys.exit()
print("YES") | 10 | PYTHON3 |
# -*- coding: utf-8 -*-
import sys
# from operator import itemgetter
# from fractions import gcd
# from math import ceil, floor
# from copy import deepcopy
# from itertools import accumulate
from collections import deque
# import math
# from functools import reduce
input = sys.stdin.readline
def ii(): return int(input(... | 10 | PYTHON3 |
from collections import defaultdict
n = int(input())
tr = defaultdict(int)
for i in range(n-1):
u, v = map(int, input().split())
tr[u]+=1
tr[v]+=1
for i in tr:
if tr[i]==2:
print("NO")
break
else:
print("YES") | 10 | PYTHON3 |
#include <bits/stdc++.h>
using namespace std;
const long long inf = LONG_MAX;
const long long arr = 1000000;
bool comp(pair<long long, long long> a, pair<long long, long long> b) {
if (a.first == b.first)
return a.second < b.second;
else
return a.first < b.first;
}
vector<vector<long long> > g(arr);
int mai... | 10 | CPP |
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