input stringlengths 20 127k | target stringlengths 20 119k | problem_id stringlengths 6 6 |
|---|---|---|
N = eval(input())
nums = list(map(int, input().split()))
sum_num = 0
for i in range(len(nums)):
for j in range(i+1, len(nums)):
sum_num += nums[i]*nums[j]
if sum_num > 10**9 + 7:
sum_num = sum_num%(10**9+7)
print(sum_num) | N = eval(input())
nums = list(map(int, input().split()))
rests = []
rest_sum = 0
for i in reversed(nums):
rest_sum += i
rests.append(rest_sum)
sum_num = 0
for i in range(len(nums)-1):
sum_num += nums[i]*rests[-(i+2)]
if sum_num > 10**9 + 7:
sum_num = sum_num % (10**9 + 7)
print(sum_num) | p02572 |
import itertools
n = int(eval(input()))
num_list = list(map(int, input().split()))
sum = 0
for i in itertools.combinations(num_list, 2):
x = i[0] * i[1]
sum += x
sum %= 10**9 + 7
print(sum)
| from itertools import accumulate
n = int(eval(input()))
a = list(map(int, input().split()))
b = list(accumulate(a))
sum = 0
for i in range(len(a)):
sum += a[i]*(b[-1] - b[i])
sum %= 10**9 + 7
print(sum) | p02572 |
# -*- coding: utf-8 -*-
def main():
n = int(eval(input()))
a = list(map(int, input().split()))
sum = 0
mod = 1000000007
for i in range(n-1):
for j in range(i+1, n):
sum += a[i]*a[j]
print((sum%mod))
if __name__ == '__main__':
main() | # -*- coding: utf-8 -*-
from itertools import accumulate
def main():
n = int(eval(input()))
a = list(map(int, input().split()))
a_sum = (accumulate(reversed(a)))
a_sum = list(reversed(list(a_sum)))
sum = 0
mod = 1000000007
for i in range(n-1):
sum += a[i]*a_sum[i+1]
print((sum%mod))
if __name__ == '__main__':
main() | p02572 |
N=int(eval(input()))
A=list(map(int,input().split()))
ans = 0
for i in range(N-1):
ans += A[i]*(sum(A[i+1:]))
#print(A[i+1:])
print((ans%((10**9)+7)))
| N=int(eval(input()))
A=list(map(int,input().split()))
sumA = sum(A)
ans = 0
for i in range(N-1):
x = A[i]
sumA -= x
ans += sumA*x
print((ans%((10**9)+7)))
| p02572 |
import math
import collections
import itertools
def resolve():
N=int(eval(input()))
A=list(map(int,input().split()))
MOD=10**9+7
ans=0
for i in range(N-1):
for j in range(i+1,N):
ans=ans%MOD+(A[i]*A[j])%MOD
print(ans)
resolve() | import math
import collections
import itertools
def resolve():
N=int(eval(input()))
A=list(map(int,input().split()))
B=[0]*N
B[N-1]=A[N-1]
MOD=10**9+7
for j in range(N-2,0,-1):
B[j]=(B[j+1]+A[j])%MOD
ans=0
for i in range(N-1):
ans=ans%MOD+(A[i]*B[i+1])%MOD
print((ans%MOD))
resolve()
| p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
a = 10**9+7
ans = 0
for i in range(N):
b = 0
for j in range(i+1,N):
b += A[j]
b = b % a
ans += A[i]*b
ans = ans % a
print(ans) | N = int(eval(input()))
A = list(map(int, input().split()))
a = 10**9+7
sumA = sum(A)
ans = 0
for i in range(N):
sumA -= A[i]
ans += A[i] * sumA
ans %= a
print(ans) | p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
ans=0
for i in range(n-1):
ans+=a[i]*sum(a[i+1:])
if ans>(10**9+7):
ans=ans%(10**9+7)
print(ans) | n=int(eval(input()))
a=list(map(int,input().split()))
s=sum(a)
ans=0
for i in range(n-1):
s-=a[i]
ans+=a[i]*s
if ans>(10**9+7):
ans=ans%(10**9+7)
print(ans) | p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
s=sum(a)
ans=0
for i in range(n-1):
s-=a[i]
ans+=a[i]*s
if ans>(10**9+7):
ans=ans%(10**9+7)
print(ans) | n=int(eval(input()))
a=list(map(int,input().split()))
s=sum(a)
ans=0
for i in range(n-1):
s-=a[i]
ans+=a[i]*s
print((ans%(10**9+7)))
| p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
def mod10_9_7(num):
return num % (10**9+7)
ans = 0
for i in range(N-1):
for j in range(i, (N)):
if i != j:
ii = A[i]
jj = A[j]
if ii > 10 ** 5 or jj > 10 ** 5:
ii = mod10_9_7(ii)
jj = mod10_9_7(jj)
ans += ii*jj
print((mod10_9_7(ans))) | N = int(eval(input()))
A = list(map(int, input().split()))
def mod10_9_7(num):
return num % (10**9+7)
seki = A[-1]
ans = 0
for i in range(N-2, -1, -1):
ans += A[i] * seki
seki += A[i]
print((mod10_9_7(ans)))
| p02572 |
def main():
N = int(eval(input()))
A_list = list(map(int, input().split()))
mod = 10**9 + 7
ans = 0
for i in range(N):
A = A_list[i]
A_ = A_list[i+1:]
ans = (ans + (A * sum(A_) % mod)) % mod
print(ans)
return
if __name__ == '__main__':
main()
| def main():
N = int(eval(input()))
A_list = list(map(int, input().split()))
mod = 10**9 + 7
ans = 0
A_ = sum(A_list) % mod
for i in range(N-1):
A = A_list[i]
A_ = A_ - A
ans = (ans + (A * A_) % mod) % mod
print(ans)
return
if __name__ == '__main__':
main()
| p02572 |
n = int(eval(input()))
la = list(map(int, input().split()))
ans = 0
for i in range(n-1):
ans = (ans%(10**9+7) + la[i+1]*sum(la[:i+1])%(10**9+7))%(10**9+7)
print(ans) | n = int(eval(input()))
la = list(map(int, input().split()))
MOD = (10**9+7)
ans = 0
nn = 0
for i in range(n):
ans %= MOD
ans += la[i]%MOD
nn %= MOD
nn += (la[i]**2)%MOD
ans = (ans**2-nn+10**9+7)*pow(2, -1, MOD)%MOD
print(ans) | p02572 |
n = int(eval(input()))
a = list(map(int,input().split()))
ans = 0
for i in range(n-1):
ans += a[i]*sum(a[i+1:])
ans = ans%(10**9+7)
print(ans) | n = int(eval(input()))
a = list(map(int,input().split()))
sum_a = sum(a)
ans = 0
for i in range(n-1):
sum_a-=a[i]
ans += a[i]*sum_a
ans = ans%(10**9+7)
print(ans) | p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
list1=[]
ans=0
for i in range(n):
ans+=(a[i]*sum(a[i+1:n]))%(10**9+7)
print((ans%(10**9+7))) | n=int(eval(input()))
a=list(map(int,input().split()))
ans=0
suma=sum(a)
for i in range(n):
suma-=a[i]
ans+=(a[i]*(suma))%(10**9+7)
print((int(ans%(10**9+7))))
| p02572 |
n = int(eval(input()))
nums = list(map(int, input().split()))
sum_value = 0
for i in range(n-1):
for j in range(i+1,n):
sum_value += nums[i]*nums[j]
print((sum_value%1000000007))
| N = int(eval(input()))
A = list(map(int, input().split()))
mod = 1000000007
ans = 0
n = A[0]
for a in A[1:]:
ans += a * n
n += a
print((ans%mod))
| p02572 |
n=int(eval(input()))
lst=list(map(int,input().strip().split()))
s=0
mod=1000000007
for i in range(0,n):
for j in range(i+1,n):
s+=(((lst[i]%mod)*(lst[j]%mod))%mod)
print((s%mod)) | n=int(eval(input()))
lst=list(map(int,input().strip().split()))
s1=sum(lst)
num=s1*s1
denom=0
mod=1000000007
for i in range(0,n):
denom+=(lst[i]*lst[i])
print((((num-denom)//2)%mod)) | p02572 |
import itertools
mod = 10 ** 9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
arr = list(itertools.combinations(a, 2))
for i, j in arr:
ans += i * j
print((ans % mod))
| n = int(eval(input()))
a = list(map(int, input().split()))
mod = 10 ** 9 + 7
ans = 0
for i in range(n):
ans += a[i] * sum(a[(i + 1):])
print((ans % mod))
| p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10**9+7
ans = 0
for i in range(N-1):
for j in range(i+1, N):
ans += A[i] * A[j]
ans = ans % mod
print(ans) | N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10**9+7
sums = []
current_sum = 0
for a in A[1:][::-1]:
current_sum += a
sums.append(current_sum)
sums = sums[::-1]
ans = 0
for a, b in zip(A[:-1], sums):
ans += a * b
ans = ans % mod
print(ans) | p02572 |
N=int(eval(input()))
An=list(map(int,input().split()))
mod=10**9+7
S=0
for i in range(N):
for j in range(N):
if i<j:
S += An[i]*An[j]
print((S%mod))
| N=int(eval(input()))
An=list(map(int,input().split()))
mod=10**9+7
s=sum(An)
S=0
num = 0
for i in range(N):
num += An[i]
S += (An[i]*(s-num))
print((S%mod)) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
s = 0
for i in range(n-1):
v = 0
for j in range(i+1, n):
v += a[j]
s += (a[i] * v % (10**9 + 7))
s %= (10**9 + 7)
print(s)
| n = int(eval(input()))
a = list(map(int, input().split()))
s = 0
ss = 0
for i in range(n):
j = n - i - 1
s += (a[j] * ss % (10**9 + 7))
s %= (10**9 + 7)
ss += a[j]
print(s)
| p02572 |
def sekiwa(x):
n = len(x)
result = 0
MOD = 1000000007
for i in range(n-1):
for j in range(i+1, n):
N = nums[i]*nums[j] % MOD
result += N
result = result % MOD
return result
n = int(eval(input()))
nums = list(map(int, input().split()))
print((sekiwa(nums))) | MOD = 1000000007
n = int(eval(input()))
nums = list(map(int, input().split()))
x = sum(nums)
y = sum([(nums[i]**2) for i in range(n)])
print((((x**2 - y)//2)% MOD)) | p02572 |
n=int(eval(input()))
a=list(map(int, input("").split()))
o=0
for i in range(n-1):
for j in range(i+1,n):
o+=a[i]*a[j]
o%=10**9+7
print(o) | n=int(eval(input()))
a=list(map(int, input("").split()))
o=0
aa=[]
for i in a:
aa.append(i**2)
s=sum(a)
o=(s**2-sum(aa))//2
o%=10**9+7
print(o) | p02572 |
def main():
n = int(eval(input()))
a = list(map(int, input().split()))
mod = 10**9 + 7
answer = 0
for i in range(0, n-1):
sum_other = sum(a[i+1:])
answer += a[i] * sum_other
if answer >= mod:
answer %= mod
print(answer)
'''
for i in range(n):
sum_sub = 0
for j in range(i+1, n):
sum_sub += a[j]
if sum_sub >= mod:
sum_sub %= mod
answer += a[i] * sum_sub
if answer >= mod:
answer %= mod
print(answer)
'''
'''
for i in range(n):
for j in range(i+1, n):
answer += a[i] * a[j]
if answer >= mod:
answer %= mod
print(answer)
'''
if __name__ == "__main__":
main()
| def main():
n = int(eval(input()))
a = list(map(int, input().split()))
mod = 10**9 + 7
answer = 0
sum_a = sum(a) % mod
for i in range(n):
sum_a = sum_a - a[i]
answer += a[i] * sum_a
answer %= mod
print(answer)
'''
for i in range(n):
sum_sub = 0
for j in range(i+1, n):
sum_sub += a[j]
if sum_sub >= mod:
sum_sub %= mod
answer += a[i] * sum_sub
if answer >= mod:
answer %= mod
print(answer)
'''
'''
for i in range(n):
for j in range(i+1, n):
answer += a[i] * a[j]
if answer >= mod:
answer %= mod
print(answer)
'''
if __name__ == "__main__":
main()
| p02572 |
from itertools import combinations
N = int(eval(input()))
A = list(map(int, input().split()))
ans = 0
for c in list(combinations(A, 2)):
tmp = 1
for e in c:
tmp *= e
ans += tmp % (10**9 + 7)
print((ans % (10**9 + 7))) | import sys
input = sys.stdin.readline
N = int(eval(input()))
A = list(map(int, input().split()))
A_sum_s = sum(A) ** 2
for e in A:
A_sum_s -= e ** 2
print((A_sum_s // 2 % (10**9 + 7))) | p02572 |
k = int(eval(input()))
num = input().split()
ass = 0
for i in range(k):
for j in range(i+1,k):
n1 = int(num[i]) % (10**9 + 7)
n2 = int(num[j]) % (10**9 + 7)
n3 = n1 * n2
ass += n3
ass = ass % (10**9 + 7)
ass = ass % (10**9 + 7)
ans = ass % (10**9 + 7)
print(ans) | k = int(eval(input()))
num = input().split()
l = 0
ass = 0
ans = 0
for i in range(k):
l += int(num[i])
for i in range(k):
l -= int(num[i])
ass += int(num[i]) * l
ans = ass % (10**9 + 7 )
print(ans) | p02572 |
import sys
input = sys.stdin.readline
N = int(eval(input()))
A = list(map(int, input().split()))
d = 1000000000 + 7
s = 0
for i in range(N):
s += A[i] * sum(A[i+1:])
print((s % d)) | import sys
input = sys.stdin.readline
N = int(eval(input()))
A = list(map(int, input().split()))
d = 1000000000 + 7
s = 0
sum_list = [A[0]]
for a in A[1:]:
sum_list.append(a + sum_list[-1])
for i in range(N):
s += A[i] * (sum_list[N-1] - sum_list[i])
print((s % d)) | p02572 |
import itertools
N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
combi = list(itertools.combinations(list(range(N)), 2))
S = 0
for x in combi:
S = (S + A[x[0]] * A[x[1]]) % mod
print(S)
| N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
S = 0
for x in range(N):
for y in range(1, N - x, 1):
S = (S + A[x] * A[x + y]) % mod
print(S)
| p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
S = 0
for x in range(N):
for y in range(1, N - x, 1):
S = (S + A[x] * A[x + y]) % mod
print(S)
| N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
sumA = sum(A)
S = 0
for x in range(N):
sumA -= A[x]
S = (S + A[x] * (sumA)) % mod
print(S)
| p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
sum = 0
mod = 10 ** 9 + 7
for i in range(N):
for j in range(N - i - 1):
sum += A[i] * A[N -1 - j]
print((sum % mod)) | N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
sum = sum(A) ** 2
squ = 0
for i in range(N):
squ += A[i] ** 2
answer = int(((sum - squ) // 2 ) % mod)
print(answer) | p02572 |
n = int(eval(input()))
Ai = list(map(int, input().split()))
sum_ans = 0
divied_num = 10**9 + 7
for i in range(n-1):
for j in range(i+1, n):
sum_ans += Ai[i] * Ai[j]
sum_ans = sum_ans % divied_num
print(sum_ans) | n = int(eval(input()))
Ai = list(map(int, input().split()))
sum_ans = sum(Ai)
ans = 0
mod = 1000000007
for i in range(n-1):
sum_ans -= Ai[i]
ans += sum_ans * Ai[i]
ans %= mod
print(ans) | p02572 |
times = int(eval(input()))
numbers = list(map(int, input().split()))
result = 0
for i in range(times):
for j in range(i+1, times):
result += numbers[i] * numbers[j]
print((result % (10 ** 9 + 7)))
| times = int(eval(input()))
numbers = list(map(int, input().split()))
result = 0
sum_numbers = sum(numbers)
calc = []
for i in range(times - 1):
sum_numbers -= numbers[i]
calc.append(sum_numbers)
for i in range(times - 1):
calc[i] *= numbers[i]
print((sum(calc) % (10 ** 9 + 7))) | p02572 |
N = int(eval(input()))
Al = input().split()
A = list( map((lambda x: int(x)), Al))
num = 0
ma = 10**9 + 7
for i in range(N):
num = (num + A[i]*sum(A[i+1:])) % ma
print(num)
| N = int(eval(input()))
Al = input().split()
A = list( map((lambda x: int(x)), Al))
num = 0
ma = 10**9 + 7
li = 0
for i in range(N-1, 0, -1):
li += A[i]
num += A[i-1] * li
num = num % ma
print(num)
| p02572 |
import itertools
x = 10**9 + 7
n = int(eval(input()))
a = list([i % x for i in list(map(int, input().split(" ")))])
ans = 0
for i in range(n):
for j in range(i + 1, n):
ans += (a[i] * a[j]) % x
print((ans % x)) | import itertools
x = 10**9 + 7
n = int(eval(input()))
a = list([i % x for i in list(map(int, input().split(" ")))])
sum_a = []
prev = 0
for i in a:
sum_a.append(prev + i)
prev = prev + i
ans = 0
for i in range(n):
ans += (a[i] * (sum_a[n-1] - sum_a[i] )) % x
print((ans % x)) | p02572 |
n=int(eval(input()))
sum=0
a=list(map(int, input().split()))
for i in range(n):
for j in range(i+1, n):
#print(i,j)
sum+=a[i]*a[j]
sum = sum%((10**9)+7)
print(sum)
| n=int(eval(input()))
sums=0
a=list(map(int, input().split()))
b = sum(a)
for i in range(n):
b -= a[i]
sums += a[i]*b
sums = sums%((10**9)+7)
print(sums)
| p02572 |
from collections import defaultdict
N=int(eval(input()))
A=list(map(int,input().split()))
P=1000000007
z=0
bm=defaultdict(lambda:0)
for i in range(0,N-1):
for j in range(i+1,N):
if(0!=bm[(A[i],A[j])]):
p=bm[(A[i],A[j])]
else:
p=A[i]*A[j]
bm[(A[i],A[j])]=p
# print(i,j,p)
z+=p
z%=P
print(z)
| N=int(eval(input()))
A=list(map(int,input().split()))
s=sum(A)
ss=s
z=0
for i in range(0,N-1):
ss-=A[i]
z+=A[i]*ss
print((z%1000000007))
| p02572 |
N = int(eval(input()))
A = [int(i) for i in input().split()]
res = 0
for i in range(N-1):
for j in range(i+1, N):
res = (res + A[i]*A[j]) % (10**9+7)
print(res) | N = int(eval(input()))
A = [int(i) for i in input().split()]
B = [0]*N
res = 0
B[N-1] = A[N-1]
for i in range(1, N):
B[N-i-1] = B[N-i] + A[N-i-1]
for i in range(N-1):
res = (res + A[i] * B[i+1]) % (10**9+7)
print(res) | p02572 |
n = int(eval(input()))
lis = list(map(int, input().split()))
mod = (10**9) +7
ans = 0
for i in range(n-1):
for j in range(i+1, n):
t = (lis[i]*lis[j])
ans += t
print((ans%mod)) | n = int(eval(input()))
lis = list(map(int, input().split()))
mod = 10**9+7
s = sum(lis)
tmp = 0
for i in lis:
tmp += i**2
print((((s*s - tmp)//2) % mod)) | p02572 |
N = int(eval(input()))
A = list(map(int,input().split()))
mod = 10**9 + 7
ans = 0
for i in range(len(A)-1):
#print(A[i+1:])
ans += (A[i] * sum(A[i+1:]))
print((ans % mod)) | N = int(eval(input()))
A = list(map(int,input().split()))
mod = 10**9 + 7
ans = 0
X = sum(A)
for i in range(len(A)-1):
Y = A[i]
X -= Y
ans += (Y * X)
print((ans % mod)) | p02572 |
from sys import stdin
def mod(val):
res = val % (10 ** 9 + 7)
if (res < 0):
res += (10 ** 9 + 7)
return res
def main():
_in = [_.rstrip() for _ in stdin.readlines()]
N = int(_in[0]) # type:int
A_arr = list(map(int, _in[1].split(' '))) # type:list(int)
# vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
A_arr_mod = [0] * len(A_arr)
for i, a in enumerate(A_arr):
A_arr_mod[i] = mod(a)
ans = 0
for i in range(N-1):
ans += A_arr_mod[i] * sum(A_arr_mod[i+1:])
ans = mod(ans)
# ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
print(ans)
if __name__ == "__main__":
main()
| from sys import stdin
def mod(val):
res = val % (10 ** 9 + 7)
if (res < 0):
res += (10 ** 9 + 7)
return res
def main():
_in = [_.rstrip() for _ in stdin.readlines()]
N = int(_in[0]) # type:int
A_arr = list(map(int, _in[1].split(' '))) # type:list(int)
# vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
A_arr_mod = [0] * len(A_arr)
for i, a in enumerate(A_arr):
A_arr_mod[i] = mod(a)
ans = 0
cache = sum(A_arr_mod)
for i in range(N-1):
cache -= A_arr_mod[i]
ans += A_arr_mod[i] * cache
ans = mod(ans)
# ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
print(ans)
if __name__ == "__main__":
main()
| p02572 |
import sys
si = sys.stdin.readline
def main():
n = int(si())
l = [int(e) for e in si().split()]
mod, ans = 10**9+7, 0
for i in range(n):
for j in range(i+1, n):
ans = (ans+(l[i]*l[j]) % mod) % mod
print(ans)
if __name__ == '__main__':
main()
| import sys
si = sys.stdin.readline
def main():
n = int(si())
l = [int(e) for e in si().split()]
tot = sum(l)
mod, ans = 10**9+7, 0
for i in range(n-1):
h = l[i]
tot -= h
ans = (ans+(tot*h) % mod) % mod
print(ans)
if __name__ == '__main__':
main()
| p02572 |
import sys
input = sys.stdin.readline
mod = int(1e9+7)
n=int(eval(input()))
L=list(map(int,input().split()))
total = 0
for i in range(n):
for j in range(i+1,n):
total+=((L[i]%mod)*(L[j]%mod))%mod
print((total%mod))
| import sys
input = sys.stdin.readline
mod = int(1e9+7)
n=int(eval(input()))
L=list(map(int,input().split()))
total = 0
hb = sum(L)
val = 0
for i in range(n-1):
val +=L[i]
total += L[i]*(hb-val)
print((total%mod))
| p02572 |
n=int(eval(input()))
L=[int(x) for x in input().split()]
sum=0
mod=1000000007
for i in range(n-1):
for j in range(i+1,n):
sum+=(L[i]*L[j])%mod
print((sum%mod))
| n=int(eval(input()))
L=[int(x) for x in input().split()]
sum=0
product=0
mod=1000000007
for i in range(n):
sum+=L[i]%mod
for i in range(n-1):
sum-=(L[i]%mod)
product+=sum*(L[i]%mod)
print((product%mod)) | p02572 |
#!/usr/bin/env python3
N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
ans = 0
for i in range(N - 1):
ans += (A[i] * (sum(A[i + 1:]) % mod)) % mod
ans = ans % mod
print(ans)
| #!/usr/bin/env python3
N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
s = sum(A)** 2
a = 0
for i in A:
a += (i ** 2)
ans = (s - a) // 2
ans = ans % mod
print(ans)
| p02572 |
def main():
eval(input()) # n
array = [int(x) for x in input().split()]
mod = 10 ** 9 + 7
ans = 0
for i, ai in enumerate(array):
for aj in array[i + 1:]:
ans += ai * aj
ans %= mod
return ans
if __name__ == '__main__':
print((main()))
| from itertools import accumulate
def main():
n = int(eval(input()))
array = [int(x) for x in input().split()]
acc = accumulate(array)
mod = 10 ** 9 + 7
ans = 0
for i, ai in enumerate(acc):
if i == n - 1:
continue
ans += ai * array[i + 1]
ans %= mod
return ans
if __name__ == '__main__':
print((main()))
| p02572 |
import sys
import math
import itertools
import bisect
from copy import copy,deepcopy
from collections import deque,Counter
from decimal import Decimal
def s(): return eval(input())
def i(): return int(eval(input()))
def S(): return input().split()
def I(): return list(map(int,input().split()))
def L(): return list(input().split())
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
INF = 10**9
mod = 10**9+7
N = i()
A = l()
ans = 0
for i in range(N-1):
for j in range(i+1,N):
ans = (ans+A[i]*A[j])%mod
print(ans) | import sys
import math
import itertools
import bisect
from copy import copy,deepcopy
from collections import deque,Counter
from decimal import Decimal
def s(): return eval(input())
def i(): return int(eval(input()))
def S(): return input().split()
def I(): return list(map(int,input().split()))
def L(): return list(input().split())
def l(): return list(map(int,input().split()))
def lcm(a,b): return a*b//math.gcd(a,b)
sys.setrecursionlimit(10 ** 9)
INF = 10**9
mod = 10**9+7
N = i()
A = l()
ans = 0
num = sum(A)
for i in range(N-1):
num -= A[i]
ans = (ans+A[i]*num)%mod
print(ans) | p02572 |
import itertools
if __name__ == '__main__':
n = int(eval(input()))
A = list(map(int,input().split()))
total = 0
C = list(itertools.combinations(A, 2))
B = [v[0]*v[1] for v in C]
print((sum(B)%(10**9+7)))
| if __name__ == '__main__':
n = int(eval(input()))
A = list(map(int,input().split()))
#全体
sm = sum(A) ** 2
#共通部分
com = sum([i * i for i in A])
ans = (sm - com) // 2
print((ans%(10**9+7))) | p02572 |
n = int(eval(input()))
a = list(map(int,input().split()))
ans_sum = 0
for i in range(n):
ans_sum += a[i] * sum(a[i+1:])
print((ans_sum%(10**9+7)))
| n = int(eval(input()))
a = list(map(int,input().split()))
mod = 10**9+7
S = sum(a) % mod
ans_sum = 0
for i in range(n-1):
S -= a[i]
ans_sum += a[i] * S
print((ans_sum%mod))
| p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
mod = 10**9+7
ans = 0
for i in range(n-1):
aa = a.pop()
# print(a,aa)
ans += (aa * sum(a)) % mod
ans %= mod
print((ans%mod)) | n=int(eval(input()))
a=list(map(int,input().split()))
mod = 10**9+7
ans = 0
aa = 0
for i in range(n-1):
aa += a.pop()
# print(a,aa)
ans += (aa * a[-1]) % mod
ans %= mod
print((ans%mod)) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split(' ')))
total = 0
for i in range(n-1):
for j in range(i+1, n):
total = (((a[i] * a[j]) % 1000000007) + total) % 1000000007
print(total)
| mod = 1000000007
n = int(eval(input()))
a = list(map(int, input().split(' ')))
b = [0] * (n + 1)
for i, v in enumerate(a):
b[i+1] = (b[i] + v) % mod
ans = 0
for i in range(n):
ans = (((a[i] * (b[n] - b[i+1])) % mod) + ans) % mod
print(ans)
| p02572 |
def main():
N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10**9 + 7
answer = 0
for i in range(N):
answer = answer % mod + A[i] % mod * sum(A[i+1:]) % mod
print(answer)
main()
| N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10**9 + 7
sq_sum = sum([x*x for x in A])
sum_sq = sum(A) * sum(A)
answer = (sum_sq - sq_sum) // 2
print((answer % mod)) | p02572 |
n = int(eval(input()))
A = [*list(map(int, input().split()))]
MOD = (10**9)+7
ans = 0
# print(A)
sum_a = [0] * (n+1)
for i in range(n):
sum_a[i+1] = sum_a[i] + A[i]
# print(sum_a)
for i in range(n):
ai = A[i]
ans = (ans + ai*(sum_a[-1] - sum_a[i+1])) % MOD
# print(sum_a[-1], sum_a[i+1],sum_a[-1] - sum_a[i+1] )
# for i in range(n):
# for j in range(i+1, n):
# ans = (ans + A[i]*A[j]%MOD) % MOD
ans = (ans + MOD) % MOD
print(ans)
| n = int(eval(input()))
A = [*list(map(int, input().split()))]
MOD = (10**9)+7
S = [0] * (n+1)
for i in range(n): S[i+1] = S[i] + A[i]
ans = 0
for i in range(n): ans = (ans + A[i] * (S[-1] - S[i+1])) % MOD
ans = (ans + MOD) % MOD
print(ans)
| p02572 |
n = int(eval(input()))
A = [*list(map(int, input().split()))]
S = [0] * (n+1)
for i in range(n): S[i+1] = S[i] + A[i]
MOD = (10**9)+7
ans = 0
for i in range(n): ans = (ans + A[i] * (S[-1] - S[i+1])) % MOD
print(((ans + MOD) % MOD))
| n = int(eval(input()))
A = [*list(map(int, input().split()))]
MOD = (10**9)+7
sum_a = sum(A)
ans = 0
for i in range(n-1):
sum_a -= A[i]
ans = (ans + A[i] * sum_a) % MOD
print(((ans + MOD) % MOD))
| p02572 |
n = int(eval(input()))
A = [*list(map(int, input().split()))]
MOD = (10**9)+7
sum_a = sum(A)
ans = 0
for a in A[:n-1]:
sum_a -= a
ans += a * sum_a
ans %= MOD
print(ans)
| n = int(eval(input()))
A = [*list(map(int, input().split()))]
MOD = 10**9 + 7
ans = b = 0
for a in A:
ans += a * b
ans %= MOD
b += a
print(ans)
| p02572 |
n = int(eval(input()))
a = list(map(int,input().split()))
mod = 1000000000 + 7
ans = 0
for i in range(n):
for j in range(i+1,n,1):
pdt = 0
if i<j:
pdt = a[i] * a[j]
ans %= mod
ans += pdt
ans %= mod
print(ans) | n = int(eval(input()))
a = list(map(int,input().split()))
sum_a = sum(a)
mod = 1000000000 + 7
ans = 0
for i in range(n):
sum_a -= a[i]
pdt = a[i] * sum_a
ans += pdt
ans %= mod
print(ans) | p02572 |
# -*- coding: utf-8 -*-
import sys
def main():
N = int( sys.stdin.readline() )
A_list = list(map(int, sys.stdin.readline().split()))
mod = 10**9 + 7
S = 0
for i in range(len(A_list)-1):
for j in range(i+1, len(A_list)):
S += ( A_list[i] * A_list[j] ) % mod
S %= mod
print(S)
if __name__ == "__main__":
main()
| # -*- coding: utf-8 -*-
import sys
def main():
N = int( sys.stdin.readline() )
A_list = list(map(int, sys.stdin.readline().split()))
cum_sum = 0
A_cum_sum = []
for i in range(len(A_list)):
cum_sum += A_list[i]
A_cum_sum.append(cum_sum)
mod = 10**9 + 7
S = 0
for i in range(len(A_list)):
S += A_list[i] * ( A_cum_sum[-1] - A_cum_sum[i] )
S %= mod
print(S)
if __name__ == "__main__":
main()
| p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
MOD = 10**9 + 7
A_mod = [a%MOD for a in A]
ans = 0
for i in range(1, N):
ans = (ans + A_mod[i-1]%MOD * sum(A_mod[i:])%MOD)%MOD
print(ans) | N = int(eval(input()))
A = list(map(int, input().split()))
MOD = 10**9 + 7
A_mod = [a%MOD for a in A]
R = sum(A_mod)
ans = 0
for a in A_mod:
R -= a
ans = (ans + a%MOD * R%MOD)%MOD
print(ans) | p02572 |
n = int(eval(input()))
lst = [ int(i) for i in input().split() ]
count = 0
for i in range(len(lst)):
c = 0
for j in range(i+1, len(lst)):
c += lst[j]
count += c * lst[i]
mod = 10**9 +7
if count >= mod:
print((count%mod))
else:
print(count) | n = int(eval(input()))
a = list(map(int, input().split()))
ruiseki = 0
count = 0
for i in range(n-1):
ruiseki += a[i]
count += ruiseki * a[i+1]
mod = 10**9 + 7
if count >= mod:
print((count%mod))
else:
print(count) | p02572 |
#n, m, q = map(int, input().split())
#List = list(map(int, input().split()))
#req = [list(map(int, input().split())) for _ in range(q)]
#t = t[:-1]
#print(ans[j], end = "") 改行無しで出力
#[0]*n
#sort = sorted(a)[::-1] 降順
#if l[i] == l[j]: continue
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
min = 0
for i in range(len(a) - 1):
min += a[i]
num = (sum(a) - min) * a[i]
ans += num
print((ans % 1000000007))
| #n, m, q = map(int, input().split())
#List = list(map(int, input().split()))
#req = [list(map(int, input().split())) for _ in range(q)]
#t = t[:-1]
#print(ans[j], end = "") 改行無しで出力
#[0]*n
#sort = sorted(a)[::-1] 降順
#if l[i] == l[j]: continue
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
min = 0
new_list = list(reversed(a))
for i in range(len(new_list) - 1):
min += new_list[i]
ans += min * new_list[i+1]
print((ans % 1000000007))
| p02572 |
n = int(eval(input()))
x = [int(w) for w in input().split()]
ans = 0
mod = 10**9 + 7
for i in range(n-1):
for j in range(i+1,n):
ans += (((x[i])%mod)*(x[j]%mod))%mod
print(((ans)%mod)) | n = int(eval(input()))
x = [int(w) for w in input().split()]
ans = 0
mod = 10**9 + 7
s = sum(x)
for i in range(n):
ans += ((x[i])**2)
ans = (s**2 - ans)//2
print((ans%mod)) | p02572 |
N = int(eval(input()))
A = list(map(int,input().split()))
ans = 0
for i in range (N):
tasizann = 0
for j in range (N-i-1):
tasizann = tasizann + A[i+j+1]
tasizann = tasizann % (10**9 + 7)
S = A[i] * tasizann
S = S % (10**9 + 7)
ans = ans + S
ans = ans % (10**9 + 7)
print (ans) | N = int(eval(input()))
A = list(map(int,input().split()))
tasizann = 0
for i in range (N):
tasizann = tasizann + A[i]
nijou = tasizann**2
nijouwa = 0
for i in range (N):
nijouwa =nijouwa + A[i]**2
ans = (nijou - nijouwa)//2
ans = ans % (10**9+7)
print (ans) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(n - 1):
for j in range(i + 1, n):
ans += a[i] % (10 ** 9 + 7) * a[j] % (10 ** 9 + 7)
print((ans % (10 ** 9 + 7))) | n = int(eval(input()))
a = list(map(int, input().split()))
ans = sum(a) ** 2
for i in a:
ans -= i ** 2
print(((ans // 2) % (10 ** 9 + 7))) | p02572 |
N=int(eval(input()))
A=list(map(int,input().split()))
limit=10**9+7
for i in range(N):
A[i]=A[i]%limit
ans=0
for i in range(N-1):
ans+=(A[i]*(sum(A[i+1:])%limit))
ans=ans%limit
print(ans) | N=int(eval(input()))
A=list(map(int,input().split()))
limit=10**9+7
S=[0]
for i in range(N):
A[i]=A[i]%limit
for i in range(1,N):
S.append((S[i-1]+A[-i])%limit)
ans=0
for i in range(N-1):
ans+=A[i]*S[-1-i]
ans=ans%limit
print(ans)
| p02572 |
#!/usr/bin/env python3
import sys
MOD = 1000000007 # type: int
def solve(N: int, A: "List[int]"):
ans = 0
for i, ai in enumerate(A):
for j, aj in enumerate(A[i+1:]):
ans += (ai * aj) % MOD
print((ans % MOD))
return
# Generated by 1.1.7.1 https://github.com/kyuridenamida/atcoder-tools (tips: You use the default template now. You can remove this line by using your custom template)
def main():
def iterate_tokens():
for line in sys.stdin:
for word in line.split():
yield word
tokens = iterate_tokens()
N = int(next(tokens)) # type: int
A = [int(next(tokens)) for _ in range(N)] # type: "List[int]"
solve(N, A)
if __name__ == '__main__':
main()
| #!/usr/bin/env python3
import sys
MOD = 1000000007 # type: int
def solve(N: int, A: "List[int]"):
ans = 0
B = [sum(A[1:])]
for i, a in enumerate(A[1:-1]):
B.append(B[i] - a)
for i, ai in enumerate(A[:-1]):
ans += (ai * B[i]) % MOD
print((ans % MOD))
return
# Generated by 1.1.7.1 https://github.com/kyuridenamida/atcoder-tools (tips: You use the default template now. You can remove this line by using your custom template)
def main():
def iterate_tokens():
for line in sys.stdin:
for word in line.split():
yield word
tokens = iterate_tokens()
N = int(next(tokens)) # type: int
A = [int(next(tokens)) for _ in range(N)] # type: "List[int]"
solve(N, A)
if __name__ == '__main__':
main()
| p02572 |
#!/usr/bin/env python3
import sys
MOD = 1000000007 # type: int
def solve(N: int, A: "List[int]"):
ans = 0
B = [sum(A[1:])]
for i, a in enumerate(A[1:-1]):
B.append(B[i] - a)
for i, ai in enumerate(A[:-1]):
ans += (ai * B[i]) % MOD
print((ans % MOD))
return
# Generated by 1.1.7.1 https://github.com/kyuridenamida/atcoder-tools (tips: You use the default template now. You can remove this line by using your custom template)
def main():
def iterate_tokens():
for line in sys.stdin:
for word in line.split():
yield word
tokens = iterate_tokens()
N = int(next(tokens)) # type: int
A = [int(next(tokens)) for _ in range(N)] # type: "List[int]"
solve(N, A)
if __name__ == '__main__':
main()
| #!/usr/bin/env python3
import sys
MOD = 1000000007 # type: int
def solve(N: int, A: "List[int]"):
ans = 0
B = [sum(A[1:])]
for i, a in enumerate(A[1:-1]):
B.append(B[i] - a)
for i, ai in enumerate(A[:-1]):
ans += (ai * B[i])
print((ans % MOD))
return
# Generated by 1.1.7.1 https://github.com/kyuridenamida/atcoder-tools (tips: You use the default template now. You can remove this line by using your custom template)
def main():
def iterate_tokens():
for line in sys.stdin:
for word in line.split():
yield word
tokens = iterate_tokens()
N = int(next(tokens)) # type: int
A = [int(next(tokens)) for _ in range(N)] # type: "List[int]"
solve(N, A)
if __name__ == '__main__':
main()
| p02572 |
count = int(eval(input()))
a = list(map(int, input().split()))
mod = 10**9 + 7
sum = 0
for i in range(len(a)-1):
for j in range(i+1, len(a)):
temp = a[i] * a[j]
sum += temp
answer = sum % mod
print(answer)
| count = int(eval(input()))
a = list(map(int, input().split()))
mod = 10**9 + 7
ans = 0
sum = sum(a)
for i in range(count):
sum = sum - a[i]
ans += sum * a[i]
answer = ans % mod
print(answer)
| p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
M = 10**9 + 7
for n in range(N):
A[n] = A[n] % M
ans = 0
for i in range(N-1):
for n in range(i + 1, N):
ans += A[i] * A[n]
ans = ans % M
print(ans) | N = int(eval(input()))
A = list(map(int, input().split()))
M = 10**9 + 7
Total = sum(A) -A[0]
ans = 0
for i in range(N-1):
ans += A[i] * Total
ans = ans % M
Total -= A[i+1]
print(ans) | p02572 |
n = int(eval(input()))
al = list(map(int, input().split()))
ans = 0
for i in range(n-1):
for j in range(i+1,n):
ans += al[i]*al[j]
ans %= 10**9+7
print(ans) | n = int(eval(input()))
al = list(map(int, input().split()))
s = sum(al)
ss = 0
m = 10**9+7
d = 500000004
for a in al:
ss += a*a
print((((s*s-ss)%m*d)%m)) | p02572 |
N=int(eval(input()))
A=input().split()
A=[int(i) for i in A]
S=0
A_sum=[]
for i in range(N):
sum=0
for j in range(i+1,N):
sum+=A[j]
A_sum.append(sum)
for i in range(N-1):
S+=A[i]*A_sum[i]
print((S%(pow(10,9)+7))) | N=int(eval(input()))
A=input().split()
A=[int(i) for i in A]
S=0
A_sum=0
for i in range(N):
A_sum+=A[i]
B=A_sum
for i in range(N):
B-=A[i]
S+=A[i]*B
print((S%(pow(10,9)+7))) | p02572 |
MOD = 10**9+7
n = int(eval(input()))
a = list(map(int, input().split()))
# print(n, a)
res = 0
for i in range(0, n-1):
for j in range(i+1, n):
# print(a[i], a[j], a[i]*a[j])
res += a[i]*a[j]
print((res%MOD)) | MOD = 10**9+7
n = int(eval(input()))
a = list(map(int, input().split()))
a1 = sum(a)
a2 = sum([x*x for x in a])
print((((a1**2-a2)//2)%MOD)) | p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
ans = 0
for i in range(len(A)):
ans += A[i] * sum(A[0:i])
ans = ans % 1000000007
print(ans)
| N = int(eval(input()))
A = list(map(int, input().split()))
ans = 0
a_sum = 0
for i in range(len(A)):
ans += A[i] * a_sum
a_sum += A[i]
ans = ans % 1000000007
print(ans)
| p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
sum_A = 0
for i in range(N-1):
sum_A += A[i]*sum(A[i+1:N])
sum_A %= 10**9+7
print(sum_A) | N = int(eval(input()))
A = list(map(int, input().split()))
ans = 0
sum_A = [0]*N
for j in range(N-1, 0, -1):
sum_A[j] = A[j]+sum_A[(j+1) % N]
for i in range(N-1):
ans += A[i]*sum_A[i+1]
ans %= 10**9+7
print(ans) | p02572 |
N=int(eval(input()))
A=list(map(int,input().split()))
ans=0
for i in range(N-1):
for j in range(i+1,N):
ans+=(A[i]*A[j])%(10**9+7)
ans=ans%(10**9+7)
print(ans)
| N=int(eval(input()))
A=list(map(int,input().split()))
ans=0
for i in range(N-1):
temp=0
for j in range(i+1,N):
temp+=A[j]
ans+=A[i]*(temp%(10**9+7))
print((ans%(10**9+7)))
| p02572 |
N=int(eval(input()))
A=list(map(int,input().split()))
ans=0
for i in range(N-1):
temp=0
for j in range(i+1,N):
temp+=A[j]
ans+=A[i]*(temp%(10**9+7))
print((ans%(10**9+7)))
| N=int(eval(input()))
A=list(map(int,input().split()))
ans=0
s=sum(A)
for i in range(N-1):
s-=A[i]
ans+=(A[i]*(s))%(10**9+7)
print((ans%(10**9+7)))
| p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
i = 0
ans = 0
tmp = 0
while(i < n - 1):
j = 1
while(i + j < n):
tmp += a[i + j]
j += 1
ans += (a[i] * tmp) % (10**9 + 7)
i+=1
tmp = 0
ans = ans % (10**9 + 7)
print(ans) | n = int(eval(input()))
a = list(map(int, input().split()))
i = 0
tmp = 0
tmpura = 0
while(i < n):
tmp += a[i]
i+=1
tmp=tmp **2
i = 0
while (i < n):
tmpura += a[i]**2
i+=1
tmpura=tmpura
ans = ((tmp - tmpura)//2)%(10**9+7)
print(ans) | p02572 |
N = int(eval(input()))
A = list(map(int,input().split()))
SUMA = sum(A)
MOD = 10**9 + 7
C = [0] * (N-1)
for i in range(N-1):
SUMA -= A[i]
C[i] = SUMA
ans = 0
for i in range(N-1):
ans += A[i]*C[i]
ans %= MOD
print(ans) | N = int(eval(input())) #入力する整数
A = list(map(int,input().split())) #入力する数列A
SUMA = sum(A) #数列の和
MOD = 10**9 + 7 # mod
C = [0] * (N-1) #累積和数列
for i in range(N-1): #\sum_{j = i+1}^{N}を求めて数列に代入する
SUMA -= A[i]
C[i] = SUMA
ans = 0 #求める答え
for i in range(N-1):
ans += A[i]*C[i]
ans %= MOD #その都度modで割った余りにする
print(ans) #答えを出力する
#計算量はO(N)です。
| p02572 |
N = int(eval(input()))
As = list(map(int, input().split()))
S = 0
for i in range(N - 1):
T = 0
for j in range(N - i - 1):
# print(As[i], As[i + 1 + j])
T += As[i + 1 + j]
T = T % 1000000007
S += As[i] * T
print((S % 1000000007)) | N = int(eval(input()))
As = list(map(int, input().split()))
S = 0
T = 0
for i in range(N):
S += As[i]
T += (As[i] * As[i]) % 1000000007
# print(S)
# print(T)
A = S*S % 1000000007
B = T % 1000000007
X = (A - B) % 1000000007
print(((X * int((1000000007 + 1)/2)) % 1000000007)) | p02572 |
N=int(eval(input()))
A=list(map(int, input().split()))
p,S = 0,0
for i in range(N-1):
ap = A.pop(0)
AA = sum(A)
aa = ap*AA
a = aa%1000000007
S += a
p = S%1000000007
print(p) | N = int(eval(input()))
A = list(map(int,input().split()))
mod = 10**9+7
a,s = 0,0
for i in range(N):
a += s*A[i]
s += A[i]
a %= mod
print(a) | p02572 |
import itertools
n = int(eval(input()))
a = list(map(int, input().split()))
p = list(itertools.combinations(list(range(n)), 2))
ans = 0
for i in p:
ans += a[i[0]] * a[i[1]]
ans = int(ans % (10**9+7))
print(ans) | n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(n):
ans += a[i] * sum(a[i+1:])
ans = int(ans % (10**9+7))
print(ans) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(n):
ans += a[i] * sum(a[i+1:])
ans = int(ans % (10**9+7))
print(ans) | n = int(eval(input()))
a = list(map(int, input().split()))
a_sum = sum(a)
ans = 0
for i in range(n):
a_sum -= a[i]
ans += a[i] * a_sum
ans = int(ans % (10**9+7))
print(ans) | p02572 |
import itertools
n = int(eval(input()))
a = [int(each) for each in input().split()]
result = 0
for a, b in itertools.combinations(a, 2):
result += a*b % 1000000007
print((result % 1000000007)) | n = int(eval(input()))
a = [int(each) for each in input().split()]
result = 0
s = sum(a)
for i in range(len(a)):
s = (s-a[i])
result += s % 1000000007 * a[i]
print((result % 1000000007)) | p02572 |
M = 10**9 + 7
N = int(eval(input()))
A = list(map(int, input().split()))
table = [0] * (N)
for i in range(N-1):
table[i+1] = table[i] + A[N-i-1]
table = table[::-1]
ans = 0
for i in range(N-1):
ans = (ans + table[i]*A[i]) % M
print(ans)
| M = 10**9 + 7
N = int(eval(input()))
A = list(map(int, input().split()))
print(((((sum(A)**2) - sum([x*x for x in A])) // 2) % M))
| p02572 |
N = int(eval(input()))
A = list(map(int,input().split()))
n = len(A)
z = 10 ** 9 + 7
ans = 0
x = 0
y = 0
for i in range(n - 1):
B = A[i + 1:n]
x = sum(B) % z
y = (A[i] * x) % z
ans = (ans + y) % z
print(ans) | N = int(eval(input()))
A = list(map(int,input().split()))
n = len(A)
z = 10 ** 9 + 7
ans = 0
x = sum(A)
x = x ** 2
for i in A:
y = i * i
x -= y
x = x // 2
x = x % z
print(x) | p02572 |
import itertools
n=int(eval(input()))
A=list(map(int,input().split()))
AC=list(itertools.combinations(A,2))
for i in range(len(AC)):
AC[i]=AC[i][0]*AC[i][1]%(10**9+7)
print((sum(AC)%(10**9+7))) | import itertools
n=int(eval(input()))
A=list(map(int,input().split()))
AC=list(itertools.combinations(A,2))
x=0
for i in range(n*(n-1)//2):
x+=AC[i][0]*AC[i][1]%(10**9+7)
print((x%(10**9+7))) | p02572 |
n=int(eval(input()))
A=list(map(int,input().split()))
x=0
for i in range(n-1):
for j in range(i+1,n):
x+=A[i]*A[j]%(10**9+7)
print((x%(10**9+7))) | n=int(eval(input()))
A=list(map(int,input().split()))
sumA=sum(A)
x=0
for i in range(n-1):
sumA-=A[i]
x+=A[i]*sumA
print((x%(10**9+7))) | p02572 |
n = int(eval(input()))
line = list(map(int, input().split()))
ans = 0
mod = 10**9 + 7
for i in range(n):
for j in range(i+1,n):
ans += line[i]*line[j]
if ans > mod:
ans = ans % mod
print(ans) | n = int(eval(input()))
line = list(map(int, input().split()))
ans = 0
x = sum(line)
mod = 10**9 + 7
for i in range(n):
x -= line[i]
ans += line[i] * x
if ans > mod:
ans = ans % mod
print(ans) | p02572 |
n = int(eval(input()))
a = [int(s) for s in input().split()]
b = []
val = 0
for i in range(0, n):
b.append(a[i] * sum(a[:i]))
val = sum(b)
print((val % (10 ** 9 + 7))) | n = int(eval(input()))
a = [int(s) for s in input().split()]
b = []
val = 0
sum_val= 0
for i in range(0, n):
b.append(a[i] * sum_val)
sum_val+= a[i]
val = sum(b)
print((val % (10 ** 9 + 7))) | p02572 |
#!/usr/bin/env python3
import collections as cl
import sys
def II():
return int(sys.stdin.readline())
def MI():
return list(map(int, sys.stdin.readline().split()))
def LI():
return list(map(int, sys.stdin.readline().split()))
MOD = 10 ** 9 + 7
def main():
N = II()
target = LI()
ans = 0
for i in range(N):
for j in range(i+1, N):
ans += (target[i] % MOD) * (target[j] % MOD) % MOD
ans = ans % MOD
print(ans)
main()
| #!/usr/bin/env python3
import collections as cl
import sys
def II():
return int(sys.stdin.readline())
def MI():
return list(map(int, sys.stdin.readline().split()))
def LI():
return list(map(int, sys.stdin.readline().split()))
MOD = 10 ** 9 + 7
def main():
N = II()
target = LI()
ans = 0
sums = [0] * N
sum_all = target[0]
sums[0] = target[0]
for i in range(1, N):
sum_all += target[i] % MOD
sums[i] = sums[i-1] + target[i]
for i in range(N):
ans += target[i] * (sum_all - sums[i])
ans = ans % MOD
print(ans)
main()
| p02572 |
n = int(eval(input()))
a = list(map(int, input().split(" ")))
ans = 0
den = int(1e9 + 7)
for i in range(len(a) - 1):
ans = (ans + a[i] * sum(a[i + 1:])) % den
print(ans) | n = int(eval(input()))
a = list(map(int, input().split(" ")))
ans = 0
den = int(1e9 + 7)
sum_a = [0 for i in range(len(a))]
sum_a[-1] = a[-1]
for i in range(len(a) - 1, 1, -1):
sum_a[i - 1] = sum_a[i] + a[i - 1]
for i in range(len(a) - 1):
ans = (ans + a[i] * sum_a[i + 1]) % den
print(ans) | p02572 |
import itertools
mod = 1000000007
sum = 0
N = int(eval(input()))
A = list(map(int, input().split()))
for v in itertools.combinations(A, 2):
sum += v[0] * v[1]
print((sum%mod))
| N = int(eval(input()))
A = list(map(int, input().split()))
mod = 1000000007
S = {}
S[0] = A[0]
for i in range(1, len(A)):
S[i] = S[i-1] + A[i]
ans = 0
for i in range(len(A)):
sum = S[len(S)-1] - S[i]
ans += A[i] * sum
print((ans%mod))
| p02572 |
N=int(eval(input()))
A=list(map(int,input().split()))
AA=[0]*N
for i in range(N):
AA[i]=A[i]%(10**9+7)
B=[0]*N
c=0
for i in range(N-1):
for j in range(i+1,N):
B[j]=(A[i]*AA[j])%(10**9+7)
c=(c+B[j])%(10**9+7)
print(c) | N=int(eval(input()))
A=list(map(int,input().split()))
c=0
for i in range(N):
c=c+A[i]**2
print(((sum(A)**2-c)//2%(10**9+7))) | p02572 |
from itertools import accumulate
def resolve():
MOD = 10**9+7
N = int(eval(input()))
A = list(map(int, input().split()))
Acc = [0] + list(accumulate(A))
ans = 0
for i in range(N):
ans += A[i] * (Acc[N] - Acc[i+1])
ans %= MOD
print(ans)
if __name__ == "__main__":
resolve()
|
def resolve():
MOD = 10 ** 9 + 7
N = int(eval(input()))
A = list(map(int, input().split()))
# 面積として見る: 縦*横
square = sum(A) ** 2
# 対角線
diag = sum([a * a for a in A])
ans = (square - diag) // 2
print((ans % MOD))
if __name__ == "__main__":
resolve() | p02572 |
N = int(eval(input()))
suji = list(map(int, input().split()))
goukei = 0
for i in range(N - 1):
for j in range(i + 1, N):
goukei += suji[i] * suji[j]
print((goukei % (10 ** 9 + 7))) | N = int(eval(input()))
suji = list(map(int, input().split()))
wa = sum(suji)
goukei = 0
for i in range(N):
goukei += suji[i] * (wa - suji[i])
wa -= suji[i]
print((goukei % (10 ** 9 + 7))) | p02572 |
mod = 10**9 + 7
n = int(eval(input()))
nums = list(map(int, input().split(" ")))
ans = 0
for i in range(n):
for j in range(i+1, n):
ans += (nums[i] * nums[j]) % mod
print((ans % mod)) | mod = 10**9 + 7
n = int(eval(input()))
nums = list(map(int, input().split(" ")))
ans = 0
ans = sum(nums) * sum(nums) - sum([num*num for num in nums])
print(((ans // 2) % mod)) | p02572 |
N=int(eval(input()))
A=list(map(int,input().split()))
b=0
for i in range(0,N):
if A[i]%(10**9)+7==0:
del A[i]
for i in range(0,len(A)-1):
for j in range(i+1,len(A)):
b+=A[i]*A[j]
print((b%(10**9+7))) | N=int(eval(input()))
A=list(map(int,input().split()))
b=0
c=0
for j in range(0,len(A)):
c+=A[j]
for i in range(0,len(A)):
c=c-A[i]
b+=A[i]*c
print((b%(10**9+7))) | p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
ans=0
for i in range(n):
p=a.pop()
q=sum(a)
ans+=p*q
print((ans%(10**9+7))) | n=int(eval(input()))
a=list(map(int,input().split()))
s=sum(a)
ans=0
for i in range(n-1):
s-=a[i]
ans+=s*a[i]
print((ans%(10**9+7))) | p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
s=sum(a)
ans=0
for i in range(n-1):
s-=a[i]
ans+=s*a[i]
print((ans%(10**9+7))) | n=int(eval(input()))
a=list(map(int,input().split()))
A=sum(a)
ans=0
for i in range(n):
A-=a[i]
ans+=A*a[i]
print((ans%(10**9+7))) | p02572 |
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)
N = int(eval(input()))
A = list(map(int, input().split()))
MOD = 10**9 + 7
A = [a % MOD for a in A]
res = 0
for i in range(N-1):
for j in range(i+1, N):
res += (A[i] * A[j]) % MOD
res %= MOD
print(res) | #!/usr/bin/env python3
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)
MOD = 10**9 + 7
N = int(eval(input()))
A = list(map(int, input().split()))
A = [a % MOD for a in A]
A_d = [(a * a) % MOD for a in A]
res = ((sum(A)**2) % MOD - sum(A_d) % MOD) % MOD
res = res * pow(2, MOD-2, MOD)
res %= MOD
print(res)
| p02572 |
import itertools
def main():
count = 0
n = int(eval(input()))
for i in itertools.combinations(list(map(int, input().split())), 2):
count += i[0]*i[1]
return count % (10**9+7)
if __name__ == "__main__":
print((main()))
| import itertools
def main():
count = 0
MOD = 10**9+7
n = int(eval(input()))
a = list(map(int, input().split()))
s = [0]
for i in range(n-1):
s.append((s[i]+a[i]) % MOD)
for ai, si in zip(a, s):
count += (ai*si) % MOD
return count % MOD
if __name__ == "__main__":
print((main()))
| p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
mod=10**9+7
ans=0
for i in range(n-1):
for j in range(i+1,n):
ans+=(a[i]*a[j])%mod
ans=ans%mod
print((ans%mod))
| n=int(eval(input()))
a=list(map(int,input().split()))
mod=10**9+7
tmp=a[-1]
ans=0
for i in range(n-1):
ii=n-i-2
#print(ii)
ans+=(tmp*a[ii])%mod
ans=ans%mod
tmp+=a[ii]%mod
print((ans%mod))
| p02572 |
N = int(eval(input()))
A = list(int(x) for x in input().split())
a = len(A)
sa = sorted(A)
su = 0
p = 10**9+7
for i in range(a):
su += sa[i]*(sum(sa[i+1:])%p)%p
print((su%p))
| N = int(eval(input()))
A = list(int(x) for x in input().split())
B = [0]
a = len(A)
sa = sorted(A)
su = 0
p = 10**9+7
for i in range(a):
B.append(B[i] + sa[i])
for j in range(a):
su += sa[j]*B[j]
print((su%p)) | p02572 |
from collections import deque
N = int(eval(input()))
A = list(map(int, input().split()))
#N=3
#A=[1,2,3]
q=deque(A)
#print(q)
ans=0
for i in range(N-1):
ans+=q.popleft() *sum(q)
print((ans%(10**9+7))) | from collections import deque
N = int(eval(input()))
A = list(map(int, input().split()))
#N=3
#A=[1,2,3]
q=deque(A)
#print(q)
ans=0
sums=sum(q)
#print(sums)
for i in range(N-1):
qwe=q.popleft()
ans+=qwe *(sums-qwe)
sums-=qwe
print((ans%(10**9+7))) | p02572 |
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