problem_id
stringclasses
100 values
submission_id
stringlengths
10
10
status
stringclasses
2 values
code
stringlengths
6
806
p02572
s112565958
Accepted
n = int(input()) a = list(map(int, input().split())) mod = 10**9+7 f = sum(a) ans = 0 for i in range(n): f = f-a[i] ans+= ((f*a[i])%mod) ans%=mod print(ans)
p02572
s873009783
Accepted
import sys stdin = sys.stdin def ns(): return stdin.readline().rstrip() def ni(): return int(stdin.readline().rstrip()) def nm(): return map(int, stdin.readline().split()) def nl(): return list(map(int, stdin.readline().split())) def main(): n = ni() A = nl() mod = 10 ** 9 + 7 s = sum(A) q = sum([a ** 2 for a in A]) ans = (((s * s) - q)) // 2 print(int(ans % mod)) if __name__ == '__main__': main()
p02572
s317134283
Accepted
n=int(input()) mod=10**9+7 A=list(map(int,input().split())) a=sum(A) a=(a**2) b=0 for i in range(n): b+=(A[i])**2 if a-b<0: c=a-b while c<=0: c+=mod ans=c//2 ans=ans%mod else: ans=(a-b)//2 ans=ans%mod print(ans)
p02572
s644560221
Accepted
N=int(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
s374476553
Accepted
INF=10**9+7 n=int(input()) A=list(map(int,input().split())) S=[sum(A)] ans=0 for i in range(len(A)): key=S[-1] S.append(key-A[i]) ans+=(A[i]*S[-1]) print(ans%INF)
p02572
s742527146
Accepted
import numpy as np import sys read = sys.stdin.buffer.read readline = sys.stdin.buffer.readline readlines = sys.stdin.buffer.readlines mod = 10 ** 9 + 7 def main(): ans = 0 cs = np.cumsum(np.array(a)) for i in range(n-1): s = (cs[-1] - cs[i]) % mod ans = (ans+(a[i]*int(s)) % mod) % mod return ans n, *a = map(int, read().split()) a = main() print(a)
p02572
s681716858
Accepted
def l_in(type_): return list(map(type_, input().split())) def i_in(): return int(input()) def m_in(type_): return map(type_, input().split()) def r_in(n, type_): return [type_(input()) for _ in range(n)] const = 1000000007 ans = 0 n = i_in() a = l_in(int) ins = 0 for i in range(1, n): ins += a[i-1] ans += ins * a[i] print(ans%const)
p02572
s589742000
Accepted
n=int(input()) l=list(map(int,input().split())) infin=10**9+7 s=0 for i in range(0,len(l)): s+=l[i] ans=0 for i in range(len(l)-1,0,-1): s=s-l[i] ans=(ans+l[i]*s)%infin print(ans)
p02572
s157950679
Accepted
def main(): n = int(input()) A = [int(x) for x in input().split()] mod = 10**9+7 # a_sum = sum(A) a_cum = [0] * (n+1) for i in range(n): a_cum[i + 1] = a_cum[i] + A[i] ans = 0 for i in range(len(A)-1): ans += A[i] * (a_cum[n] - a_cum[i+1]) ans %= mod print(ans) if __name__ == '__main__': main()
p02572
s266413292
Accepted
# Python template from collections import defaultdict import sys import math def get_array(): return list(map(int , sys.stdin.readline().strip().split())) def get_ints(): return map(int, sys.stdin.readline().strip().split()) def input(): return sys.stdin.readline().strip() n = int(input()) a = get_array() pre_sum = [0] for i in range(n-1,-1,-1): pre_sum.append(pre_sum[-1]+a[i]) pre_sum = pre_sum[::-1] mod = 1000000007 ans = 0 for i in range(n): ans = (ans+a[i]*pre_sum[i+1])%mod print(ans)
p02572
s849376551
Accepted
mod = 10**9+7 n = int(input()) a = list(map(int, input().split())) a.sort() ans = 0 for i in a: ans += i ans = ans**2 for i in a: ans -= i**2 print((ans//2)%mod)
p02572
s636443759
Accepted
N = int(input()) A = list(map(int, input().split())) MOD = 10 ** 9 + 7 B = [0] * (N + 1) for i in range(N): B[i + 1] = (B[i] + A[i]) % MOD ans = 0 tmp = B[-1] for i in range(N): ans += (A[i] * (tmp - B[i + 1])) % MOD ans %= MOD print (ans)
p02572
s842407016
Accepted
N=int(input()) *A,=map(int,input().split()) ra=A[::-1] S=[0]*(N+1) for i in range(N): S[i+1]=S[i]+ra[i] M=10**9+7 S=S[::-1] i=0 ans=0 while i<N: ans+=A[i]*S[i+1] ans%=M i+=1 print(ans)
p02572
s773938065
Accepted
MOD=10**9+7 N=int(input()) A=list(map(int,input().split())) ans=sum(A)**2 ans-=sum(map(lambda x: x**2, A)) ans//=2 print(ans%MOD)
p02572
s644213038
Accepted
N = int(input()) A = list(map(int, input().split())) X = 0 Ans = 0 for i in range(N - 1): X += A[i] Ans += X * A[i + 1] Ans = Ans % (10 ** 9 + 7) print(Ans)
p02572
s512894834
Accepted
import itertools n=int(input()) a=list(map(int,input().split())) b=list(itertools.accumulate(a)) ans=0 for i in range(n-1): ans+=a[-i-1]*b[-i-2] ans%=10**9+7 print(ans)
p02572
s826131805
Accepted
N=int(input()) A=list(map(int,input().split())) #437235829 mod(10^9+7) sumAcol=0 sumA=0 sumtr=0 for i in range(N): sumtr+=A[i]**2 sumAcol+=A[i] sumtr=sumtr % (10**9+7) sumAcol=sumAcol % (10**9+7) for i in range(N): sumA+=(sumAcol*A[i])%(10**9+7) sumA=(sumA-sumtr)+10**9+7 print(sumA*(5*10**8+4) % (10**9+7))
p02572
s237810850
Accepted
N=int(input()) A=list(map(int, input().split())) B=[A[0]] for i in range(1,N): B.append(B[i-1]+A[i]) p=10**9+7 ans=0 for i in range(1,N): ans+=A[i]*B[i-1] ans%=p print(ans)
p02572
s645607375
Accepted
p = 10**9+7 s = 0 s_sq = 0 N = int(input()) A = list(map(int, input().split())) for i in range(N): s += A[i] s_sq += A[i]**2 s %= p s_sq %= p print((s**2 - s_sq) * pow(2, p-2, p) % p)
p02572
s672972021
Accepted
N = int(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
s797633053
Accepted
def mod(num): return num % (10 ** 9 + 7) N = int(input()) A = list(map(int, input().split())) Asum = sum(A) ans = 0 for i, a in enumerate(A): Asum -= a ans = mod(ans + Asum * a) print(ans)
p02572
s785494304
Accepted
n=int(input()) a=list(map(int,input().split())) su=sum(a) ru=[0 for i in range(n)] ru[0]=su-a[0] for i in range(1,n): ru[i]=ru[i-1]-a[i] ans=0 for i in range(0,n-1): ans+=(a[i]*(ru[i]%1000000007))%1000000007 ans=ans%1000000007 print(ans)
p02572
s065731999
Accepted
N = int(input()) A = list(map(int,input().split())) ans = 0 suma = sum(A) for i in range(N-1): suma -= A[i]%(10**9+7) ans += (A[i] * suma )%(10**9+7) print(ans%(10**9+7))
p02572
s058110534
Accepted
n = int(input()) lst = list(map(int, input().split())) suffS = [] lst = lst[::-1] summ = 0 for i in lst: suffS.append(summ) summ += i res = 0 for i in range(n): res += suffS[i] * lst[i] res %= (10**9+7) print(res)
p02572
s637552088
Accepted
#abcdef #a*b,a*c,a*d,a*e,a*f #b*c,b*d,b*e,b*f #c*d,c*e,c*f #d*e,d*f #e*f n = int(input()) l = list(map(int,input().split())) mod = 10**9 + 7 all_l = 0 for i in range(n): all_l += l[i] all_l %= mod ans = 0 for i in range(n-1): all_l = (all_l-l[i])%mod ans += (l[i]*all_l)%mod ans %= mod print(ans)
p02572
s062558909
Accepted
#C - Sum of product of pairs N = int(input()) A = list(map(int,input().split())) SUM = 0 jsum= 0 MOD = 1000000007 for j in range(N): jsum = (jsum + A[j]) % MOD for i in range(N-1): jsum = (jsum - A[i]) % MOD SUM = ( SUM + (jsum * A[i] % MOD ) ) % MOD # 出力 print(SUM)
p02572
s621500031
Accepted
n = int(input()) a = list(map(int, input().split())) subsum = a[n-1] ans = 0 for b in reversed(a[:n-1]): ans = ans + b * subsum subsum = subsum + b print(ans % (10**9 + 7))
p02572
s467258020
Accepted
n= int(input()) mod=10**9+7 a= [int(x ) for x in input().split()] b= a[:] s=0 for i in range(n-2,-1,-1): b[i]=b[i+1]+b[i] for i in range(n): s += (b[i]-a[i])*a[i] print(s%mod)
p02572
s609804149
Accepted
n = int(input()) a = list(map(int,input().split())) count = 0 su = sum(a) for i in range(n-1): su -= a[i] count += a[i]*su print(count%(10**9+7))
p02572
s794664438
Accepted
N = int(input()) A = list(map(int, input().split())) sum_A = 0 S = [] for i in range(1,N): sum_A += A[-1*i] S.append(sum_A) ans = 0 for i in range(N-1): tmp = A[N-2-i] * S[i] ans += tmp ans = ans % (10 ** 9 + 7) print(ans)
p02572
s500638312
Accepted
MOD = 10**9+7 n = int(input()) a = list(map(int, input().split())) ans = sum(a)**2 for i in range(n): ans -= a[i]*a[i] ans //= 2 ans %= MOD print(ans)
p02572
s311042649
Accepted
def findProductSum(A, n): array_sum = sum(A) array_sum_square = array_sum ** 2 individual_square_sum = 0 for i in range(n): individual_square_sum += A[i] * A[i] return (array_sum_square - individual_square_sum) // 2 N = int(input()) A = list(map(int, input().split())) print(findProductSum(A, N)%(10**9+7))
p02572
s664506641
Accepted
n = int(input()) a = list(map(int, input().split())) nums = [0]*n nums[0] = a[0] for i in range(1,n): nums[i] = a[i]+nums[i-1] ans = 0 for i in range(n-1): ans += a[i]*(nums[n-1]-nums[i]) ans %= 10**9+7 print(ans)
p02572
s579257802
Accepted
n = int(input()) a = list(map(int, input().split())) k = 0 num = sum(a) t = 10 ** 9 + 7 for i in a: num -= i k += num * i ans = k % t print(ans)
p02572
s415659512
Accepted
N = int(input()) A = list(map(int, input().split())) #print(A) total = 0 left = 0 sum = sum(A) #print(end) for i in range(N - 1): #print(i, A[i]) left = left + A[i] #start = i + 1 #for j in range(start, N): #print(i, j) #sum = sum + A[j] #print(A[i], sum) right = sum - left #print(i, left, right, A[i]) total = (total + A[i] * right) % 1000000007 print(total)
p02572
s037979437
Accepted
def main(): N = int(input()) A = list(map(int,input().split())) SUM = [sum(A)] for i in range(1,N): SUM.append((SUM[i-1]-A[i-1])%(10**9+7)) ans = 0 for i in range(N-1): ans += A[i]*SUM[i+1] ans = ans%(10**9+7) print(ans) if __name__ == '__main__': main()
p02572
s101891070
Accepted
N = int(input()) A = input().split() toA = 0 for i in range(N): A[i] = int(A[i]) toA += A[i] ans = 0 for i in range(0, N): toA -= A[i] ans += A[i]*toA print(ans % 1000000007)
p02572
s446032013
Accepted
def c_sum_of_product_of_pairs(MOD=10**9 + 7): N = int(input()) A = [int(i) for i in input().split()] total = sum(A) cumsum = [0] for i in range(N): cumsum.append(cumsum[-1] + A[i]) return sum([(total - cumsum[i]) * A[i - 1] for i in range(1, N)]) % MOD print(c_sum_of_product_of_pairs())
p02572
s457376769
Accepted
n = int(input()) s = list(map(int, input().split())) ans= 0 total = sum(s) for i in range(len(s)-1): total -= s[i] ans += total * s[i] print(ans % (10**9 +7))
p02572
s074482372
Accepted
n = int(input()) a = list(map(int, input().split())) ans = 0 r_wa = [a[0]] for i in range(n) : if i>0 : r_wa.append(r_wa[i-1]+a[i]) for i in range(n-1) : ans += a[i]*(r_wa[n-1]-r_wa[i]) ans = ans%1000000007 print(ans)
p02572
s525138966
Accepted
n=int(input()) mod=10**9+7 a=list(map(int,input().split())) A=sum(a)%mod total=0 for i in range(n-1): A-=a[i] total+=A*a[i] total%=mod print(total)
p02572
s797614610
Accepted
n = int(input()) a_list = list(map(int, input().split())) s_2 = 0 for i in a_list: s_2 += i**2 ans = (sum(a_list)**2 - s_2)//2 ans = ans%(10**9+7) print(ans)
p02572
s886591328
Accepted
N = int(input()) A = list(map(int, input().split())) M = 10 ** 9 + 7 T = sum(map(lambda x: x**2, A)) print (((sum(A)**2-T)//2)%M)
p02572
s797163616
Accepted
MOD = 1000000007 N = int(input()) A = list(map(int, input().split())) ans = 0 B = [0]*(N-1) sumA = sum(A) for i in range(1, N): sumA -= A[i-1] B[i-1] = sumA for i in range(0, N-1): ans += A[i] * B[i] ans %= MOD print(ans)
p02572
s455368427
Accepted
N = int(input()) A = list(map(int, input().split())) mod = 10**9 + 7 tot = sum(A) ans = 0 for i in range(N): tot -= A[i] lin = tot * A[i] ans += lin % mod ans %= mod print(ans)
p02572
s175705755
Accepted
n = int(input()) a = list(map(int, input().split())) l = [0] mod = 10 ** 9 + 7 s = sum(a) cur = 0 ans = 0 for i in range(n): cur += a[i] ans += (a[i] * (s - cur)) % mod ans %= mod print(ans)
p02572
s702237652
Accepted
N = int(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 print(ans%((10**9)+7))
p02572
s507610379
Accepted
N = int(input()) a = list(map(int,input().split())) ans = 0 total = 0 for i in range(N): if i != 0: total += a[i-1] ans += a[i]*total print(ans%(10**9 + 7))
p02572
s306987972
Accepted
N = int(input()) x = list(map(int, input().split())) s = sum(x) - x[0] ans = 0 for i in range(N-1): ans = ans + x[i]*s s = s - x[i+1] ans = ans % 1000000007 print(ans)
p02572
s935802201
Accepted
N = int(input()) A = list(map(int,input().split())) mod = 10**9 + 7 ans = 0 A_sum = [0] for i in range(N): A_sum.append(A_sum[-1] + A[i]) for i in range(N-1): ans += A[i] * (A_sum[N] - A_sum[i+1]) ans %= mod print(ans)
p02572
s695191878
Accepted
N = int(input()) A_list = list(map(int, input().split())) #myans_list = [ [0 for n in range(N)] for nn in range(N) ] #myans = 0 #for n in range(N): # for nn in range(N): # myans_list[n][nn] = A_list[n] * A_list[nn] #for n in myans_list: # print(n) mysum = sum(A_list) myans = 0 for n in range(N-1): mysum -= A_list[n] myans += mysum*A_list[n] print(myans%(1000000007))
p02572
s502538795
Accepted
N = int(input()) A = list(map(lambda x: int(x), input().split(' '))) res = ((sum(A)**2 - sum(list(map(lambda x: x**2, A)))) // 2) % (10**9 + 7) print(int(res))
p02572
s308498072
Accepted
import sys, math, itertools, collections, bisect input = lambda: sys.stdin.buffer.readline().rstrip().decode('utf-8') inf = float('inf') ;mod = 10**9+7 mans = inf ;ans = 0 ;count = 0 ;pro = 1 n = int(input()) A = list(map(int,input().split())) S = sum(A) % mod for i in range(n): S =(S- A[i]) % mod ans += S * A[i] ans %= mod print(ans)
p02572
s534508872
Accepted
n = int(input()) a = list(map(int, input().split())) ans = 0 for i in range(2,n+1): a[-i] += a[-i+1] for i in range(len(a)-1): ans = ans % 1000000007 + ((a[i] - a[i+1]) * a[i+1]) % 1000000007 print(ans % 1000000007)
p02572
s133605225
Accepted
p = 10**9+7 def pow(x,m): if m==0: return 1 if m==1: return x if m%2==0: return (pow(x,m//2)**2)%p else: return (x*(pow(x,(m-1)//2)**2)%p)%p N = int(input()) A = list(map(int,input().split())) a0 = ((sum(A)%p)*(sum(A)%p))%p a1 = 0 for i in range(N): a1 = (a1+A[i]**2)%p a = a0-a1 a = (pow(2,p-2)*a)%p print(a)
p02572
s603455919
Accepted
N=int(input()) L=list(map(int,input().split())) ans=0 a=sum(L) mod=1000000007 for i in range(N): ans+=L[i]*(a-L[i]) ans%=mod if ans%2==0: print(ans//2) else: print((ans+mod)//2)
p02572
s573771098
Accepted
n = int(input()) A = list(map(int, input().split())) mod = 10**9+7 s = sum(A) ans = 0 for i in range(n): s -= A[i] ans += (A[i] * s) % mod print(ans%mod)
p02572
s319428231
Accepted
N = int(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
s134354585
Accepted
N = int(input()) A = list(map(int, input().split())) mod = 10**9 + 7 ans = 0 total = sum(A) for i in range(N - 1): total -= A[i] ans += (A[i] * total) print(ans % mod)
p02572
s392567920
Accepted
n=int(input()) a=list(map(int,input().split())) mod=10**9+7 cnt=sum(a) ans=0 for i in range(n): ans+=a[i]*(cnt-a[i]) ans%=mod cnt-=a[i] print(ans)
p02572
s085883491
Accepted
n = int(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
s755345035
Accepted
ans = 0 N = int(input()) array = list(map(int, input().split())) x = sum(array) y = 0 for i in range(N): y += array[i]**2 ans = x**2 -y print((ans//2)%(10**9+7))
p02572
s838693031
Accepted
N = int(input()) A = list(map(int, input().split())) T = sum(A) ans = 0 for i in range(N): T -= A[i] ans += A[i] * T ans %= 10 ** 9 + 7 print(ans)
p02572
s621203385
Accepted
n=int(input()) s=list(map(int ,input().split())) sum=[0]*n sum[-1]=s[-1] for i in range(n-2,-1,-1): sum[i]=sum[i+1]+s[i] ans=0 for i in range(n-1): ans=ans+sum[i+1]*s[i] print(ans%(1000000007))
p02572
s312834483
Accepted
N = int(input()) A = list(map(int, input().split())) s = 0 for i in range(N): s += A[i] ans = 0 for i in range(N-1): s -= A[i] p = A[i] * s p %= (10 ** 9 + 7) ans += p print(ans%(10 ** 9 + 7))
p02572
s099561894
Accepted
import numpy as np def main(): n = int(input()) As = list(map(int, input().split())) mod = 10 ** 9 + 7 As_sum = sum(As) ans = 0 for i in range(n): As_sum -= As[i] ans += As_sum * As[i] ans %= mod ans %= mod print(ans) if __name__ == "__main__": main()
p02572
s739675334
Accepted
n = int(input()) a = list(map(int, input().split())) p = 1000000007 z = 0 for i in range(n): z += a[i] z = z % (2 * p) y = (z ** 2) % (2 * p) x = 0 for j in range(n): x += a[j] ** 2 x = x % (2 * p) w = int(((y - x) / 2) % p) print(w)
p02572
s794712031
Accepted
mod=10**9+7 N=int(input()) A=list(map(int,input().split())) B=[0 for i in range(N)] B[0]=sum(A)-A[0] count=(A[0]*B[0])%mod for i in range(1,N): B[i]=B[i-1]-A[i] count=(count+A[i]*B[i])%mod print(count)
p02572
s962900269
Accepted
def main(): N = int(input()) A = list(map(int,input().split())) ans = 0 m0 = 10**9+7 Ar = [0]*N sum0 = 0 for i in reversed(range(N)): sum0 = (sum0 + A[i]) % m0 Ar[i] = sum0 for i in range(N-1): ans = (ans + A[i] * Ar[i+1]) % m0 print(ans) if __name__ == '__main__': main()
p02572
s436954909
Accepted
N = int(input()) A = [int(i) for i in input().split()] mod = 10 ** 9 + 7 sum = [0] * N A = A[::-1] sum[0] = A[0] for i in range(1, N) : sum[i] = (sum[i - 1] + A[i]) % mod sum = sum[::-1] A = A[::-1] ret = 0 for i in range(N - 1) : ret += A[i] * sum[i + 1] % mod ret %= mod print(ret)
p02572
s795026830
Accepted
n = int(input()) al = list(map(int, input().split())) mod = 10**9+7 ans = sum(al)**2 for ai in al: ans -= ai**2 print((ans//2)%mod)
p02572
s249694872
Accepted
N = int(input()) A = list(map(int,input().split())) S = sum(A) S2 = sum(map(lambda x: x*x,A)) ans = ((S*S - S2)//2)%1000000007 print(int(ans))
p02572
s404763898
Accepted
def main(): n = int(input()) a_list = list(map(int, input().split())) sum_list = [0 for _ in range(n)] sum_list[0] = sum(a_list) ans = 0 for i in range(1, n): sum_list[i] = sum_list[i - 1] - a_list[i - 1] for i in range(n - 1): ans += a_list[i] * sum_list[i + 1] % (10 ** 9 + 7) print(ans % (10 ** 9 + 7)) if __name__ == "__main__": main()
p02572
s024713329
Accepted
N = int(input()) A = list(map(int, input().split())) answer = 0 x = 0 for i in range(len(A) - 1): x += A[i] answer += (x * A[i + 1]) print(answer% (10**9 + 7))
p02572
s423055723
Accepted
N = int(input()) A = list(map(int,input().split())) MOD = 10**9+7 cums = [0] for a in A: cums.append(cums[-1] + a) ans = 0 for i,a in enumerate(A): ans += a*(cums[-1] - cums[i+1]) ans %= MOD print(ans)
p02572
s000659084
Accepted
N = int(input()) A = list(map(int, input().split())) wa = 0 a = 0 for l in range(N-1): a += A[N-l-1] wa += a * A[N-l-2] print(wa % (10**9+7))
p02572
s243266277
Accepted
import sys def input(): return sys.stdin.readline().rstrip() def main(): n = int(input()) A = list(map(int,input().split())) mod = 10**9 + 7 sum_A = sum(A)%mod ans = 0 for a in A: sum_A -= a ans += a*sum_A%mod print(ans%mod) if __name__=='__main__': main()
p02572
s078360890
Accepted
N = int(input()) A = list(map(int,input().split())) B = sum(A) new_A = A.reverse() n = 0 for i in range(N-1): n += A[i]*(B-A[i]) B = B-A[i] print(n%(10**9+7))
p02572
s192755010
Accepted
n=int(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
s054566695
Accepted
n = int(input()) a = list(map(int,input().split())) mod = 10**9+7 s = sum(a) ans = 0 for i in range(n): s -= a[i] ans += s*a[i] ans %= mod print(ans%mod)
p02572
s502882283
Accepted
n = int(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
s579469854
Accepted
n = int(input()) a = list(map(int, input().split())) b = sum(a) ans = 0 for i in range(0, n): b = b - a[i] ans = ans + a[i] * b ans = ans % 1000000007 print(ans)
p02572
s845141284
Accepted
import numba from numba import njit, b1, i4, i8, f8 import numpy as np # noqa N = int(input()) A = [int(x) for x in input().split()] def main(A): ans = 0 s = 0 for i in range(N - 2, -1, -1): s += A[i + 1] s %= 10**9 + 7 ans = (ans + A[i] * s) % (10**9 + 7) return ans print(main(A))
p02572
s066282235
Accepted
n=int(input()) a=list(map(int,input().split())) ans=0 x=0 for i in range(n): ans += a[i] * x x +=a[i] print(ans%(10**9+7))
p02572
s278664909
Accepted
N = int(input()) A = list(map(int,input().split())) S = 0 S2 = 0 MOD = 1000000007 for i in range(N): S += A[i] S2 += A[i]*A[i] print((S*S-S2)//2%MOD)
p02572
s063216514
Accepted
N = int(input()) A = list(map(int, input().split())) ans = 0 mod = int(1e9 + 7) s = sum(A) % mod for a in A: s -= a ans += (a * s) % mod ans %= mod print(int(ans))
p02572
s054996969
Accepted
N = int(input()) A = list(map(int, input().split())) mod = 10**9 + 7 tmp_sum = sum(A) ans = 0 for i in range(N-1): tmp_sum -= A[i] ans += tmp_sum*A[i] print(ans%mod)
p02572
s905957325
Accepted
N = int(input()) A = list(map(int, input().split())) mod = 1000000007 S = 0 for i in range(N): S += A[i] sum = 0 for i in range(N): S -= A[i] if S<0: S+= mod sum += int(A[i]*S%mod) sum = int(sum%mod) print(sum)
p02572
s332984267
Accepted
N = int(input()) A = list(map(int,input().split())) mod = 10**9 + 7 sum_A = sum(A) ans = 0 for i in range(N): sum_A -= A[i] ans += (A[i]*sum_A) print(ans%mod)
p02572
s767577646
Accepted
def modinv(val, mod): b, u, v = mod, 1, 0 while b: t = val // b val = val - t * b val, b = b, val u = u - t * v u, v = v, u u = u % mod return u n = int(input()) a = list(map(int, input().split())) mod = 10 ** 9 + 7 total = 0 for item in a: total = (total + item) % mod total = (total * total) % mod for item in a: total = (total - (item * item)) % mod print(total * modinv(2, mod) % mod)
p02572
s034159805
Accepted
n = int(input()) a = list(map(int, input().split())) ans = 0 c = sum(a) for i in range(n - 1): c = c - a[i] ans += a[i] * c print(ans % (10 ** 9 + 7))
p02572
s240419909
Accepted
N = int(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
s613451333
Accepted
import itertools n = int(input()) a = list(map(int,input().split())) cumsum = list(itertools.accumulate(a)) ans = 0 mod = 10**9+7 for i in range(1,n): ans += a[i]*cumsum[i-1] print(ans%mod)
p02572
s607178590
Accepted
import sys input = sys.stdin.readline def main(): ans = 0 mod = (10**9)+7 n = int(input()) a = list(map(int, input().split())) suma = sum(a) for i in range(n-1): suma -= a[i] ans += a[i]*suma print(ans%mod) if __name__ == '__main__': main()
p02572
s169479134
Accepted
n = int(input()) a_array = map(int, input().split()) MOD = 10 ** 9 + 7 a_array = [a % MOD for a in a_array] sum = 0 square_sum = 0 for i in range(n): sum += a_array[i] sum %= MOD square_sum += pow(a_array[i], 2, MOD) square_sum %= MOD ans = pow(sum, 2, MOD) - square_sum ans *= 500000004 ans %= MOD print(ans)
p02572
s350213569
Accepted
import sys def main(): N = int(input()) A = list(map(int, input().split())) sum_A = sum(A) cum_A = [sum_A] for a in A[:N-1]: cum_A.append(cum_A[-1] - a) res = 0 mod = 1000000007 for i, a in enumerate(cum_A[1:]): res += A[i] * a res %= mod print(res) if __name__ == "__main__": main()
p02572
s104130121
Accepted
n = int(input()) list1 = list(map(int,input().split())) mod = 10 ** 9 + 7 total = 0 y = sum(list1) for i in range(0,n-1): y = y- list1[i] total += list1[i] * y % mod total = total % mod print(total)
p02572
s287295707
Accepted
N = int(input()) A = list(map(int, input().split())) ans = 0 S = sum(A) - A[0] for i in range(0, N-1): ans = (ans + A[i] * S) % (10**9+7) S -= A[i+1] print(ans)
p02572
s130846496
Accepted
def s():return int(input()) def mp():return map(int,input().split()) a = s() b = list(mp()) ans=0 t = sum(b)%(10**9+7) for i in range(a): t-=b[i] ans+=b[i]*t ans%=(10**9+7) print(ans)
p02572
s690385254
Accepted
N = int(input()) int_list = list(map(int, input().split())) sum_num = 0 sum_temp = sum(int_list[1:]) for i in range(N-1): sum_num += int_list[i] * sum_temp sum_temp -= int_list[i+1] print(sum_num % (10 ** 9 + 7))