problem_id
stringclasses
100 values
submission_id
stringlengths
10
10
status
stringclasses
2 values
code
stringlengths
6
806
p02572
s839293889
Accepted
import sys input = sys.stdin.readline n = int(input()) A = list(map(int,input().split())) mod = 10**9 + 7 B = [A[0]] for i in range(1, n): B.append((B[-1] + A[i]) % mod) ans = 0 for i in range(n-1,0,-1): ans = (ans + B[i-1] * A[i]) print(ans%mod)
p02572
s756005627
Accepted
n = int(input()) a = list(map(int,input().split())) MOD = 10**9+7 array_sum = 0 for i in range(n): array_sum += a[i] array_sum %= MOD ans = 0 for i in range(n): array_sum -= a[i] ans += array_sum * a[i] ans %= MOD print(ans)
p02572
s311200198
Accepted
import itertools n=int(input()) a_list=list(map(int,input().split())) sum=0 ps = list(itertools.accumulate(a_list)) for i in range(n-1): sum+=a_list[i]*(ps[n-1]-ps[i]) s=sum%(10**9+7) print(s)
p02572
s302901826
Accepted
N = int(input()) A = list(map(int, input().split())) p = int(1e9 + 7) result = 0 total = 0 for i in range(N - 1, 0, -1): total = (total + A[i]) % p result = (result + A[i-1] * total) % p print(result)
p02572
s861505180
Accepted
N = int(input()) A = map(int,input().split()) ans = 0 ans2 = 0 mod = 10 ** 9 + 7 for a in A: ans += a ans2 += a**2 print(((ans **2 - ans2)//2)%mod)
p02572
s106137971
Accepted
n = int(input()) a = list(map(int, input().split())) mod = pow(10, 9) + 7 s = sum(a) % mod ans = s * s % mod for i in a: ans -= i * i ans %= mod ans = ans * pow(2, mod - 2, mod) % mod print(ans)
p02572
s128469427
Accepted
import sys input = lambda : sys.stdin.readline().rstrip() M = (10**9)+7 n = int(input()) As = map(int, input().split(" ")) cumsum = [] cur = 0 out = 0 for i in range(n-1): cur += As[i] out += cur*As[i+1] out = out % M print(out)
p02572
s643796129
Accepted
from itertools import accumulate def main(): N = int(input()) A = list(map(int, input().split())) B = [0] + list(accumulate(A)) MOD = 10 ** 9 + 7 ans = 0 for i in range(N): ans += A[i] * (B[N] - B[i+1]) ans %= MOD print(ans) if __name__ == "__main__": main()
p02572
s434016005
Accepted
n = int(input()) A = list(map(int, input().split())) mod = 10 ** 9 + 7 summ = 0 quadsum = 0 for k in range(n): summ = (summ + A[k]) % mod quadsum = (quadsum + A[k]*A[k])%mod ans = (summ*summ)%mod - quadsum if ans % 2 == 1: ans += mod ans = (ans/2)%mod print(int(ans))
p02572
s183816103
Accepted
n = int(input()) arr = list(map(int,input().split())) ans = 0 tmp = 0 for i in range(n-1): tmp += arr[i]%1000000007 ans += tmp*arr[i+1] % 1000000007 print(ans%1000000007)
p02572
s024892390
Accepted
mod=10**9+7 N=int(input()) A=list(map(int,input().split())) B=[0] for x in A: B.append(B[-1]+x) ans=0 for i in range(N): s=(B[N]-B[i+1])%mod ans+=A[i]*s ans%=mod print(ans)
p02572
s527765882
Accepted
N = int(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
s706647791
Accepted
from sys import exit, stdin input = stdin.readline import copy # from collections import deque,Counter import numpy as np nmod = 1000000007 (N,) = list(map(int, input().split())) A = list(map(int, input().split())) ans = 0 tsum = 0 for i in range(N - 1, 0, -1): tsum += A[i] tsum %= nmod tmp = (A[i - 1] * tsum) % nmod ans += tmp ans %= nmod print(int(ans))
p02572
s936154891
Accepted
n=int(input()) A=list(map(int,input().split())) def twosekisum(A): return (sum(A)**2-sum([i**2 for i in A]))//2 print(twosekisum(A)%(10**9+7))
p02572
s627902455
Accepted
N = int(input()) A = list(map(int,input().split())) Sum = sum(A) ans = 0 for i in range(N): Sum = Sum-A[i] AA = Sum*A[i] ans += AA ans = ans%(10**9 + 7) print(ans)
p02572
s553196755
Accepted
MOD = 1000000007 n = int(input()) a = [int(_) for _ in input().split()] p = [0] * (n + 1) for i in range(n - 1, -1, -1): p[i] = p[i + 1] + a[i] ans = 0 for i in range(n): add = a[i] * (p[i] - a[i]) add = add % MOD ans += add ans = ans % MOD print(ans)
p02572
s108053834
Accepted
import sys import math import fractions from collections import defaultdict import copy stdin = sys.stdin ns = lambda: stdin.readline().rstrip() ni = lambda: int(stdin.readline().rstrip()) nm = lambda: map(int, stdin.readline().split()) nl = lambda: list(map(int, stdin.readline().split())) N=int(input()) A=nl() mod=10**9+7 sum_a=sum(A) ans=0 for i in range(N): sum_a=sum_a-A[i] ans+=sum_a*A[i] ans%=mod print(ans)
p02572
s639238003
Accepted
n = int(input()) A = list(map(int, input().split())) sumA = sum(A) sumB = 0 sumC = sumA for i in range(n): sumC = sumC- A[i] sumB += A[i] * sumC print(sumB % (10**9 + 7))
p02572
s059692230
Accepted
n = int(input()) x = list(map(int, input().strip().split())) sum=0 minsum=0 for i in range(0,n): minsum += x[i] for i in range(0,n-1): minsum-=x[i] sum += x[i]*minsum if(sum>10**9+7): sum%=(10**9+7) print(sum)
p02572
s550513895
Accepted
N = int(input()) A = list(map(int, input().split())) MOD = 1000000007 a = 0 b = 0 for i in range(N): a += A[i] % MOD b += (A[i] ** 2) % MOD a = a ** 2 ans = (a - b) * pow(2, MOD - 2, MOD) % MOD print(ans)
p02572
s624294127
Accepted
n = int(input()) a = list(map(int, input().split())) MOD = 10 ** 9 + 7 sum = sum(a) % MOD ans = 0 for i in range(len(a)): sum -= a[i] sum %= MOD ans += a[i] * sum ans %= MOD print(ans)
p02572
s368544387
Accepted
def main(): n = int(input()) a = list(map(int, input().split())) a.reverse() temp = 0 a_sum = [] for i in range(len(a)): temp += a[i] a_sum.append(temp) total = 0 a_sum.reverse() a.reverse() for i in range(1, len(a_sum)): total += a[i-1]*a_sum[i] print(total % (10**9+7)) if __name__ == '__main__': main()
p02572
s049688546
Accepted
n=int(input()) a=list(map(int,input().split())) ans=0 wa=sum(a) for i in range(n): wa-=a[i] ans=(ans+(wa*a[i]))%(10**9+7) print(ans)
p02572
s692246026
Accepted
N = int(input()) A = list(map(int, input().split())) prefix = [0] for a in A: prefix.append(prefix[-1] + a) res = 0 M = 10 ** 9 + 7 for i, a in enumerate(A[:-1], start=1): res += a * (prefix[N] - prefix[i]) res %= M print(res)
p02572
s496148800
Accepted
n = int(input()) a = list(map(int,input().split())) sum_a = sum(a) ans = 0 for i in a: sum_a -= i ans += i * sum_a ans %= 10**9 + 7 print(ans)
p02572
s885915460
Accepted
N = int(input()) A = list(map(int, input().split())) MOD = 10**9 + 7 S = sum(A) % MOD ans = (S ** 2) % MOD for a in A: ans -= a**2 ans %= MOD ans *= pow(2, MOD-2, MOD) ans %= MOD print(ans)
p02572
s543771532
Accepted
################ C n = int(input()) nums = list(map(int, input().split())) total = 0 total_sum = sum(nums) for num in nums: total_sum -= num total += num * total_sum print(total % 1000000007)
p02572
s872817238
Accepted
def resolve(): N = int(input()) A = [int(i) for i in input().split(maxsplit=N)] presum = [0 for _ in range(N + 1)] for i in range(N): presum[i + 1] = presum[i] + A[i] sumA = 0 for i in range(1, N): sumA += (A[i] * (presum[i])) % (10**9 + 7) print(sumA % (10**9 + 7)) resolve()
p02572
s421592650
Accepted
n = int(input()) a = list(map(int, input().split())) s = 0 ans = 0 mo = 10 ** 9 + 7 for i in range(n): ans += s * a[i] s += a[i] print(ans % mo)
p02572
s745112238
Accepted
def solve(): N = int(input()) A = list(map(int, input().split())) sum_a = 0 tmp = 0 for i in range(N-1): tmp += A[i] sum_a += tmp * A[i+1] # print(sum_a) ans = sum_a % 1000000007 print(ans) if __name__ == "__main__": solve()
p02572
s965282886
Accepted
def resolve(): n=int(input()) a = list(map(int, input().split())) are=10**9+7 s=sum(a) ans=0 for i in range(n): s-=a[i] ans+=a[i]*s ans=ans%are print(ans) resolve()
p02572
s523240768
Accepted
def findProductSum(A, n): array_sum = sum(A) array_sum_square = array_sum ** 2 individual_square_sum = 0 for i in range(0, n, 1): individual_square_sum += A[i] * A[i] return (array_sum_square - individual_square_sum) // 2 n = input() arr = list(map(int, input().split())) res = findProductSum(arr, len(arr)) % (10**9 + 7) print(res)
p02572
s293835559
Accepted
# C - Sum of product of pairs from itertools import accumulate def main(): N, *A = map(int, open(0).read().split()) rev_cumsum = list(accumulate(reversed(A[1:])))[::-1] MOD = 10 ** 9 + 7 res = sum(a * c for a, c in zip(A[:-1], rev_cumsum)) % MOD print(res) if __name__ == "__main__": main()
p02572
s206950677
Accepted
N = int(input()) A = list(map(int, input().split())) mod = 10 ** 9 + 7 sum_a = 0 for a in A: a = a % mod sum_a = (sum_a + a) % mod ans = 0 for a in A: sum_a = (sum_a - a) % mod ans += (a % mod) * sum_a ans = ans % mod print(ans % mod)
p02572
s207987826
Accepted
N = int(input()) A = [int(s) for s in input().split()] mod = 10**9+7 wa = 0 wa_list = [] for i in range(N)[::-1]: if i == 0: break wa += A[i] wa_list.append(wa) wa_list.reverse() ans = 0 for i in range(N-1): seki = A[i]*wa_list[i] ans += seki print(ans % mod)
p02572
s467951014
Accepted
import collections from functools import lru_cache import bisect INF = float("inf") ZERO = 0 ONE = 1 def read(): return input().strip() def readInt(): return int(input().strip()) def readList(): return list(map(int, input().strip().split())) def solve(N, arr): ans = 0 MOD = 10**9 + 7 totalSum = sum(arr) % MOD currSum = 0 for num in arr: currSum += num ans = (ans + num * (totalSum - currSum)) % MOD return ans % MOD N = readInt() arr = readList() print(solve(N, arr))
p02572
s218889641
Accepted
import numpy N = int(input()) A = list(map(int, input().split())) res = [] res.append(A[0]) for i in range(len(A)-1): res.append(res[i] + A[i+1]) sum = 0 for i in range(N-1): sum += A[i] * (res[N - 1] - res[i]) print(sum % (10**9+7))
p02572
s548734225
Accepted
n = int(input()) li_a = list(map(int, input().split())) answer = 0 su = sum(li_a) mo = (10 ** 9) + 7 for idx, a in enumerate(li_a): su = su - a answer += (a * su) print(answer % mo)
p02572
s584299079
Accepted
n=int(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
s684605571
Accepted
N = int(input()) A = list(map(int,input().split())) mod = 10**9+7 S = sum(A)**2 SS = 0 for i in range(N): SS += A[i]**2 print(((S - SS)//2)%mod)
p02572
s689012331
Accepted
# -*- coding: utf-8 -*- def main(N, A_list): total_list = [] total = 0 for i in range(len(A_list)): total += A_list[i] total_list.append(total) num = 0 for i in range(len(A_list)-1): num += A_list[i] * (total_list[len(A_list)-1]-total_list[i]) val = num % ((10 ** 9) + 7) print(val) N = int(input()) A_list = list(map(int, input().split())) main(N, A_list)
p02572
s708211931
Accepted
N=int(input()); X=list(map(int,input().split())) s=0;t=0; for i in range(N): s+=X[i]; t+=X[i]*X[i]; print(((s*s-t)//2)%1000000007)
p02572
s832519565
Accepted
n = int(input()) a = list(map(int,input().split())) ans = sum(a)**2 mod = 10**9 + 7 for i in range(n): ans -= a[i]**2 ans //= 2 print(ans%mod)
p02572
s970826450
Accepted
N,*A = map(int, open(0).read().split()) s = 0 m = 1000000007 for x in A: s = (s+x) % m ans = 0 for x in A: s = (s-x) % m ans = (ans+x*s) % m print(ans)
p02572
s408108220
Accepted
import numpy as np n = int(input()) lst = list(map(int,input().split())) s = 0 t = 0 for x in lst: s += x t += (x ** 2) % (10**9+7) w = (s**2-t) % (10**9+7) if w % 2 == 0: print(w//2) else: print((w+10**9+7)//2)
p02572
s905486900
Accepted
N = int(input()) A = list(map(int, input().split())) B = sum(A) cnt = 0 for i in range(N-1): B -= A[i] cnt += A[i]*B print(cnt%((10**9)+7))
p02572
s647453223
Accepted
import sys readline = sys.stdin.readline N = int(readline()) A = list(map(int,readline().split())) DIV = 10 ** 9 + 7 ans = 0 cur = 0 for i in range(1, N): cur += A[i - 1] ans += A[i] * cur ans %= DIV print(ans)
p02572
s314354163
Accepted
n=int(input()) a=list(map(int,input().split())) mod=10**9+7 import numpy as np cum=[] prev=0 for i in range(n): tmp = prev%mod +a[i]%mod cum.append(tmp) prev = cum[-1] ans=0 for i in range(n-1): p=a[i] t = cum[-1] - cum[i] ans+=(p*t)%mod print(ans%mod)
p02572
s619398398
Accepted
n = int(input()) a = list(map(int,input().split())) h = sum(a) ans = 0 for i in range(n): h -= a[i] ans = (ans+a[i]*(h))%(10**9+7) print(ans)
p02572
s616988636
Accepted
def read_ints(): return map(int, input().split(' ')) mod = int(1e9 + 7) def fexp(x, y): ret = 1 while y > 0: if y % 2 == 1: ret = ret * x % mod x = x * x % mod y = y // 2 return ret input() a = list(read_ints()) s = sum(a) ans = 0 for i in a: ans = (ans + i * (s - i)) % mod print(ans * fexp(2, mod - 2) % mod)
p02572
s962351494
Accepted
n=int(input()) list=input().split() sum=0 for i in range(n): sum+=int(list[i]) sum=sum*sum sum2=0 for i in range(n): sum2+=int(list[i])*int(list[i]) sum-=sum2 sum//=2 sum%=1000000007 print(int(sum))
p02572
s922645849
Accepted
N = int(input()) A = list(map(int, input().split())) mod = int(1e9) + 7 R = [0 for _ in range(N+1)] for i in range(N): R[i+1] = R[i] + A[i] S = 0 for i in range(N-1): S += A[i] * (R[N] - R[i+1]) % mod S %= mod print(S)
p02572
s722270060
Accepted
# coding: utf-8 # Your code here! import sys readline = sys.stdin.readline read = sys.stdin.read n,*a = map(int,read().split()) MOD = 10**9+7 i2 = (MOD+1)//2 r = sum(a) r *= r r -= sum(i*i for i in a) r *= i2 print(r%MOD)
p02572
s003461125
Accepted
n=int(input()) l=list(map(int,input().split())) b=sum(l)**2 a=0 for i in range(n): a+=l[i]**2 print((b-a)//2%(10**9+7))
p02572
s348618116
Accepted
n = int(input()) a = list(map(int, input().split())) b = sum(a) ans = 0 for i in range(n-1): ans += a[i] *(b-a[i]) b = b - a[i] print(ans % (10**9 + 7))
p02572
s172046412
Accepted
MOD = 10 ** 9 + 7 n = int(input()) a = [int(x) for x in input().split()] sum = 0 for x in a: sum += x sum %= MOD ans = 0 for i in range(n): sum -= a[i] if sum < 0: sum += MOD ans += a[i] * sum ans %= MOD print(ans)
p02572
s466512703
Accepted
N=int(input()) A=list(map(int,input().split())) Mod=10**9+7 two_inverse=pow(2,Mod-2,Mod) X=sum(A)%Mod Y=0 for a in A: Y+=a*a Y%=Mod print(((X*X-Y)*two_inverse)%Mod)
p02572
s655014586
Accepted
n=int(input()) l=list(map(int,input().split())) mod=10**9+7 ans=pow(sum(l)%mod,2,mod) for i in range(n): ans-=l[i]**2 ans%=mod ans*=pow(2,mod-2,mod) print(ans%mod)
p02572
s597421579
Accepted
n=input() a = list(map(int,input().split())) suma = sum(a) r = 0 for i in range(0, len(a) - 1): suma -= a[i] r += a[i] * suma print(r % (10 ** 9 + 7))
p02572
s729697435
Accepted
mod = 1000000007 N = int(input()) A = list(map(int, input().split())) S = [0] # 累積和のリスト ans = 0 for i in range(N): S.append(A[i] + S[i] % mod) for i in range(N): sum = S[N] - S[i + 1] if sum < 0: sum += mod ans += A[i] * sum print(ans % mod)
p02572
s407308242
Accepted
n= int(input()) a = list(map(int,input().split())) allsum= sum(a) ans = 0 for i in range(n): allsum = allsum -a[i] ans += a[i]*allsum o = ans % (10**9+7) print(o)
p02572
s636590283
Accepted
n = int(input()) L = list(map(int,input().split())) L = sorted(L,reverse=True) #print(L) t = 0 a = 0 for i in range(1,n): t += L[i-1] a += (t * L[i]) #% (10**9 + 7) # print(t,a) print(a % (10**9 + 7))
p02572
s227229043
Accepted
n=int(input()) a=list(map(int,input().split())) x=sum(a)-a[0] ans=0 for i in range(n): ans = (ans + a[i]*x)%(10**9 + 7) if i!=n-1: x-=a[i+1] print(ans)
p02572
s430163463
Accepted
def main(): import sys input = sys.stdin.readline N = int(input()) A = list(map(int, input().split())) ans = 0 all_num = sum(A) for i in range(N, 1, -1): all_num -= A[i - 1] ans += A[i - 1] * all_num print(ans % (10 ** 9 + 7)) main()
p02572
s803794009
Accepted
n = int(input()) a = list(map(int, input().split())) mod = 10**9 + 7 aa = [a[0] % mod] for i in range(1, n-1): aa.append((aa[i-1] + a[i]) % mod) ans = 0 for i in range(n-1): ans += ((aa[i] * a[i+1]) % mod) print(ans % mod)
p02572
s618639696
Accepted
N = int(input()) A = list(map(int,input().split())) MOD = 10**9 + 7 S1, S2 = 0, 0 for a in A: S1 += a S2 += a * a % MOD S1 %= MOD S2 %= MOD print(((S1*S1%MOD-S2+MOD) % MOD) * pow(2,MOD-2,MOD) % MOD)
p02572
s390742712
Accepted
n=int(input()) l=list(map(int,input().split())) an=0;md=10**9+7 suf=[0]*n suf[-1]=l[-1] for i in range(n-2,-1,-1): suf[i]=suf[i+1]+l[i] for i in range(n-1): an=(an+l[i]*suf[i+1])%md print(an)
p02572
s105979348
Accepted
N = int(input()) A = list(map(int,input().split())) s = [0]*(N+1) for i in range(N): s[i+1] = s[i] + A[i] cnt = 0 for j in range(N): cnt = (cnt + (A[j]*(s[N] - s[j+1])))%(10**9+7) print(cnt)
p02572
s155890352
Accepted
n = int(input()) A = list(map(int, input().split())) M = 10 ** 9 + 7 ans = 0 B = [A[0]] for j in range(1,n): B.append(A[j]+B[j-1]) for i in range(n-1): ans += A[i] * (B[-1]-B[i]) ans %= M ans %= M print(ans)
p02572
s019637669
Accepted
n = int(input()) a = list(map(int,input().split())) mod = 10**9 + 7 s = sum(a) ans = 0 for i in a: s -= i s %= mod ans += s*i ans %= mod print(ans)
p02572
s485808352
Accepted
import sys import itertools input = sys.stdin.readline def main(): N = int(input()) A = list(map(int, input().split())) A = A[::-1] B = list(itertools.accumulate(A)) MOD = 10**9+7 ans = 0 for i in range(N - 2, -1, -1): ans = (ans + A[i + 1] * B[i]) % MOD print(ans) if __name__ == '__main__': main()
p02572
s536385392
Accepted
n = int(input()) a = list(map(int, input().split())) sum = sum(a) - a[0] ans = 0 for i in range(n): ans += a[i] * sum if (i == n-1): break else: sum -= a[i+1] ans %= 10 ** 9 + 7 print(ans)
p02572
s303740604
Accepted
N=int(input()) A=list(map(int, input().split())) MOD=7+10**9 SUM=sum(A) ans=0 for i in range(N-1): SUM-=A[i] ans += A[i]*SUM %MOD print(ans %MOD)
p02572
s785113742
Accepted
import numpy as np N = int(input()) A = list(map(int, input().split())) B = [0] * (N+1) # 累積和テーブル B[i] = sum(A[:i]) mod = 10**9 + 7 ans = 0 for i in range(N): B[i+1] = B[i] + A[i] # 累積和 for i in range(N): sum = (B[N] - B[i+1]) % mod ans += A[i] * sum ans %= mod print(int(ans))
p02572
s110448508
Accepted
m = int(input()) a = list(map(int, input().split())) mod = 10**9 + 7 ans = 0 tmp_sum = sum(a[1:m]) % mod for x in range(m-1): if a[x] % mod != 0: ans += (a[x] * tmp_sum) % mod tmp_sum -= a[x+1] % mod print(ans%mod)
p02572
s283584318
Accepted
n = int(input()) a = list(map(int,input().split())) arr = [0]*(n+1) ans = 0 mod = 10**9+7 for i in range(n): arr[i+1] += arr[i]+a[i] for i in range(n): ans += (a[i]*(arr[n]-arr[i+1]))%mod print(ans%mod)
p02572
s592975717
Accepted
n = int(input()) A = list(map(int, input().split())) mod = 10**9+7 count = 0 num = sum(A) % mod ans = 0 for a in A[:-1]: num = num-a ans = (ans+a*num) % mod print(ans)
p02572
s875960106
Accepted
import sys input = sys.stdin.readline N = int(input()) A = list(map(int, input().split())) mod = 10 ** 9 + 7 sum_A = sum(A) % mod ans = 0 for a in A[:-1]: sum_A -= a sum_A %= mod ans += a * sum_A ans %= mod ans %= mod print(ans)
p02572
s730163558
Accepted
N = int(input()) A = list(map(int, input().split())) MOD = 10**9 + 7 l = [0]*(N) for i in range(N-1): l[i+1] += (l[i] + A[i])%MOD #print(l) ans = 0 for i in range(N-1): ans += (A[N-1-i] * l[N-1-i])%MOD print(ans%MOD)
p02572
s706320770
Accepted
N=int(input()) A= list(map(int,input().split())) ans=0 S=sum(A) for i in range(N): S-=A[i] ans+=A[i]*S print(ans%(10**9+7))
p02572
s884321191
Accepted
n = int(input()) a = list(map(int, input().split())) MOD = 10 ** 9 + 7 summ = 0 ans = 0 for i in range(1, n): summ += a[-i] ans += a[-(i + 1)] * summ ans %= MOD print(ans % MOD)
p02572
s865842686
Accepted
N=int(input()) l=list(map(int,input().split())) b=10**9+7 d=(sum(l))**2 c=0 for i in range(N): c=c+l[i]**2 print((d-c)//2%b)
p02572
s658082614
Accepted
N = int(input()) data = input().split() data = [int(s) for s in data] num = 0 ans = 0 sum = sum(data) for i in range(N) : num += data[i] ans += (sum - num) * data[i] print(ans % 1000000007)
p02572
s338229038
Accepted
MOD = 10 ** 9 + 7 N = int(input()) A = list(map(int, input().split())) sumA = 0 for ai in A: sumA = (sumA + ai) % MOD ans = 0 for ai in A: sumA = sumA - ai ans = (ans + sumA * ai) % MOD print(ans)
p02572
s295301209
Accepted
n = int(input()) a = list(map(int, input().split())) mod = 10**9 + 7 all_item = sum(a) ans = 0 for i in range(n): all_item = (all_item - a[i])%mod ans = (ans + all_item*a[i])%mod print(ans)
p02572
s825366502
Accepted
n = int(input()) a_list = list(map(int,input().split())) sum_a = sum(a_list) sum = 0 for i in range(n): sum += a_list[i] * (sum_a-a_list[i]) sum = sum%(10**9+7) sum_a -= a_list[i] print(sum)
p02572
s911734711
Accepted
from itertools import accumulate n=int(input()) A=[int(i) for i in input().split()] B=list(accumulate(A)) s = 0 for i in range(n): s += A[i]*(B[-1]-B[i]) s %= (10**9+7) print(s)
p02572
s712329354
Accepted
n=int(input()) a=list(map(int,input().split())) ans=0 t=sum(a) s=0 for i in range(n): s+=a[i]*a[i] ans=(t*t-s)//2 ans=ans%(10**9+7) print(ans)
p02572
s938765343
Accepted
n=int(input()) a=list(map(int,input().split())) sum=0 mod=10**9+7 for i in range(n): sum+=a[i] sum=sum**2 for i in range(n): sum-=a[i]**2 sum=(sum//2)%mod print(sum)
p02572
s193501669
Accepted
N=int(input()) List = list(map(int, input().split())) midList = [0]*(N-1) mid = 0 for i in range(N-2,-1,-1): mid += List[i+1] midList[i] = mid res=0 for i in range(N-1): a = List[i] % 1000000007 b = midList[i] % 1000000007 res += a*b print(res%1000000007)
p02572
s120669168
Accepted
n = int(input()) a = list(map(int, input().split())) bs = 10**9 + 7 s = sum(a) sm = 0 for i, ai in enumerate(a): s -= ai sm += (ai * s) % bs sm = sm % bs print(sm)
p02572
s955767688
Accepted
n=int(input()) a=list(map(int,input().split())) b=sum(a) l=[] for i in range(len(a)-1): b-=a[i] l.append(a[i]*b) print(sum(l)%(1000000007))
p02572
s734804504
Accepted
import math N=int(input()) A=list(map(int,input().split())) ans=0 tmp=0 for i in range(N-1): tmp+=A[i] ans+=tmp*A[i+1] print(ans%((10**9)+7))
p02572
s584651454
Accepted
from itertools import accumulate mod = 10 ** 9 + 7 input() l = list(map(int, input().split())) print(sum(a * b % mod for a, b in zip(list(accumulate(l))[:-1], l[1:])) % mod)
p02572
s685597899
Accepted
N = int(input()) b = 10**9+7 A = list((int(x) for x in input().split())) sum = 0 for a in A: sum += a ans = 0 for i in range(N-1): sum -= A[i] ans += A[i]*sum print(ans % b)
p02572
s920242124
Accepted
from itertools import accumulate n = int(input()) a = list(map(int, input().split())) MOD = 10**9+7 ac = list(accumulate(a)) ans = 0 for i in range(n-1): ans += (ac[i]*a[i+1]) ans %= MOD print(ans)
p02572
s186799610
Accepted
import sys, math from functools import lru_cache sys.setrecursionlimit(10**9) MOD = 10**9+7 def input(): return sys.stdin.readline()[:-1] def mi(): return map(int, input().split()) def ii(): return int(input()) def i2(n): tmp = [list(mi()) for i in range(n)] return [list(i) for i in zip(*tmp)] def main(): N = ii() A = list(mi()) s = 0 t = 0 for i in range(N): s += A[i]*A[i] t += A[i] print(((t*t-s)//2)%MOD) if __name__ == '__main__': main()
p02572
s352753539
Accepted
n=int(input()) a=[int(x) for x in input().split()] m=10**9+7 s=sum(a) ans=0 for i in range(n-1): s-=a[i] ans+=a[i]*s ans%=m ans%=m print(ans)
p02572
s391269539
Accepted
N = int(input()) ai_char = map(str, input().split(" ")) Ai = [] for i in ai_char: Ai.append(int(i)) mod_val = 1000000007 N1 = N-1 sum = 0 sum_tmp = 0 for j in range(0, N): sum_tmp += Ai[j] for i in range(N1): sum_tmp -= Ai[i] sum += Ai[i] * sum_tmp if sum > mod_val: sum = sum % mod_val print(int(sum))
p02572
s955845179
Accepted
N = int(input()) A = [int(i) for i in input().split()] S = 0 P = 10**9 + 7 for i in range(N): S = (S + A[i])%P ans = 0 for i in range(N): S = (S-A[i]+P)%P a = (A[i]*S)%P ans = (ans + a)%P print(ans)