input
stringlengths
20
127k
target
stringlengths
20
119k
problem_id
stringlengths
6
6
if __name__ == '__main__': n = int(eval(input())) a = [int(i) for i in input().split()] mod = 10**9+7 count = 0 for i in range(n-1): for j in range(i+1,n): count += (a[i]*a[j])%mod print((count%mod))
if __name__ == '__main__': n = int(eval(input())) a = [int(i) for i in input().split()] mod = 10**9+7 sumA = sum(a) sumB = 0 count = 0 for i in range(n-1): sumB+=a[i] count += ((sumA-sumB)*a[i])%mod print((count%mod))
p02572
# -*- coding: utf-8 -*- N = int(eval(input())) A = input().split() sum = 0 for i in range(N): count = 0 for j in range(i+1, N): count += int(A[j]) sum += int(A[i]) * count print((sum % (10**9 + 7)))
# -*- coding: utf-8 -*- N = int(eval(input())) A = input().split() B = [0] for i in range(N): B.append(B[i] + int(A[i])) sum = 0 for i in range(N): sum += int(A[i]) * (B[N] - B[i+1]) print((sum % (10**9 + 7)))
p02572
N = int(eval(input())) ls = list(map(int, input().split())) m = 1000000007 ans = 0 for i in range(0, N): for j in range(i+1, N): ans += (ls[i]*ls[j]) print((ans%m))
N = int(eval(input())) ls = list(map(int, input().split())) m = 1000000007 sumNum = sum(ls) currentSum, lastAns = 0, 0 for i in range(N -1): currentSum += ls[i] lastAns = (lastAns + (ls[i] * (sumNum - currentSum))) % m print(lastAns)
p02572
N = int(eval(input())) A = list(map(int, input().split())) sum = 0 for i in range(N-1): for m in range(i+1, N): sum += A[i]*A[m] if sum > 1000000007: sum = sum%1000000007 print(sum)
N = int(eval(input())) A = list(map(int, input().split())) S = sum(A) ans = 0 for i in range(N): S -= A[i] ans += A[i] * S ans = ans % (10 ** 9 +7) print(ans)
p02572
n = int(eval(input())) A = list(map(int,input().split())) MOD = 10 ** 9 + 7 ret = 0 for i in range(n-1): for j in range(i+1,n): ret += ((A[i] %MOD) * A[j]) % MOD ret = ret % MOD print(ret)
n = int(eval(input())) A = list(map(int,input().split())) MOD = 10 ** 9 + 7 ret = 0 S = [A[0]] for i in range(1, n): S.append(S[i-1] +A[i]) for i in range(n): ret += A[i] * (S[-1]-S[i]) ret = ret % MOD print(ret)
p02572
import itertools n = int(eval(input())) a_list = list(map(int, input().split())) max = 0 mod = 10 ** 9 + 7 for a in itertools.combinations(a_list, 2): b, c = a max += b * c print((max % mod))
mod = 10 ** 9 + 7 n = int(eval(input())) a_list = list(map(int, input().split())) result = 0 a_sum = sum(a_list) for i in a_list: a_sum -= i result += i * a_sum print((result % mod))
p02572
from sys import stdin input = stdin.readline n = int(input().rstrip()) a = list(map(int, input().rstrip().split())) MOD = 1000000007 ans = 0 k = 0 s = [0] * n for i in range(n-1, 0, -1): k += a[i] % MOD s[i] = k for i in range(n-1): ans += a[i] * s[i+1] ans = ans % MOD print(ans)
from sys import stdin input = stdin.readline def cumsum(xs): result = [xs[0]] for x in xs[1:]: result.append(result[-1] + x) return result n = int(input().rstrip()) a = list(map(int, input().rstrip().split())) ans = 0 MOD = 1000000007 s = cumsum(list(reversed(a))) for i in range(n-1): ans += a[i] * s[n-2-i] ans = ans % MOD print(ans)
p02572
from sys import stdin input = stdin.readline def cumsum(xs): result = [xs[0]] for x in xs[1:]: result.append(result[-1] + x) return result n = int(input().rstrip()) a = list(map(int, input().rstrip().split())) ans = 0 MOD = 1000000007 s = cumsum(list(reversed(a))) for i in range(n-1): ans += a[i] * s[n-2-i] % MOD ans = ans % MOD print(ans)
from sys import stdin input = stdin.readline def cumsum(xs): result = [xs[0]] for x in xs[1:]: result.append(result[-1] + x) return result n = int(input().rstrip()) a = list(map(int, input().rstrip().split())) ans = 0 MOD = 1000000007 s = cumsum(list(reversed(a))) for i in range(n-1): ans += a[i] * s[n-2-i] print((ans % MOD))
p02572
n=int(eval(input())) a = list(map(int,input().split())) def p(val): print(val) sho = 10**9 +7 count = 0 for i in range(n-1): for j in range(i+1,n): count += ((a[i]%sho)*(a[j]%sho)) % sho #if count > sho: # count = count%sho p(count%sho)
n=int(eval(input())) a = list(map(int,input().split())) def p(val): print(val) sho = 10**9 +7 a1 = sum(a)**2 b1 = list([y**2 for y in a]) b2=sum(b1) result = ((a1-b2)//2)% sho p(result)
p02572
N = int(eval(input())) A = list(map(int,input().split())) l = [] n = 0 for i in range(1,N): n += A[i]*sum(A[:i]) print((n%(10**9+7)))
N = int(eval(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
import functools import operator N = int(eval(input())) A = list(map(int, input().split())) mod = 10**9+7 ans = 0 for i in range(1,N): tmp = A[i:] # print(tmp) ans += A[i-1]*sum(tmp) print((ans%mod))
import functools import operator N = int(eval(input())) A = list(map(int, input().split())) mod = 10**9+7 ans = 0 v = sum(A) for i in range(N-1): v -= A[i] ans += A[i]*v print((ans%mod))
p02572
from sys import stdin input = stdin.readline def SumOfProductParis(n): if n == 0: return 0 elif n == 1: return A[0] else: result = 0 for i in range(0, n-1): for j in range(i+1, n): result += A[i]*A[j] return result%(10**9+7) N = int(eval(input())) A = list(map(int, input().split())) print((SumOfProductParis(N)))
from sys import stdin input = stdin.readline def SumOfProductParis(n): if n == 0: return 0 elif n == 1: return A[0] else: result = 0 temp = sum(A) result = temp**2 for i in range(n): result -= A[i]**2 return (result//2)%(10**9+7) N = int(eval(input())) A = list(map(int, input().split())) print((SumOfProductParis(N)))
p02572
n = int(eval(input())) l = list(map(int,input().split())) M = 1000000007 sm = 0 for i in range(n): for j in range(i+1,n): sm = (sm%M + (l[i] * l[j])%M) % M print(sm)
n = int(eval(input())) l = list(map(int,input().split())) M = 1000000007 sm = 0 for i in l: sm = (sm + i) sms = pow(sm,2) ss = 0 for i in range(n): ss = (ss + (l[i] * l[i])) print((((sms - ss)//2)%M))
p02572
import sys sys.setrecursionlimit(10**6) n = int(eval(input())) A = list(map(int, input().split())) #n, m = map(int, input().split()) #s = input() #s,t = input().split() #a = [int(input()) for _ in range(n)] # #readline = sys.stdin.readline #n,m = [int(i) for i in readline().split()] #ab = [[int(i) for i in readline().split()] for _ in range(n)] MOD = 10**9+7 # tot = sum(A) # ans = 0 # for a in A: # ans += a*(tot-a) # ans %= MOD # ans //= 2 # ans %= MOD ans = 0 for i in range(n): for j in range(i+1,n): ans += A[i]*A[j] ans %= MOD print(ans)
import sys sys.setrecursionlimit(10**6) n = int(eval(input())) A = list(map(int, input().split())) #n, m = map(int, input().split()) #s = input() #s,t = input().split() #a = [int(input()) for _ in range(n)] # #readline = sys.stdin.readline #n,m = [int(i) for i in readline().split()] #ab = [[int(i) for i in readline().split()] for _ in range(n)] MOD = 10**9+7 tot = sum(A) tot %= MOD ans = 0 rmv = 0 for a in A: rmv += a rmv %= MOD ans += a*(tot-rmv) ans %= MOD print(ans)
p02572
N = int(eval(input())) A = list(map(int, input().split())) s = 0 for i in range(N): s += A[i] s %= (10**9+7) s = s**2 s %= (10**9+7) t = 0 for i in range(N): t += (A[i]**2 % (10**9+7)) t %= (10**9+7) ans = (s-t) % (10**9+7) ''' tmp = (2**1000000005) % (10**9+7) ''' tmp = 500000004 ans *= tmp ans %= (10**9+7) print(ans)
N = int(eval(input())) A = list(map(int, input().split())) s, t = 0, 0 for i in range(N): s += A[i] t += A[i]**2 s = s**2 ans = (s-t) % (10**9+7) # tmp = (2**1000000005) % (10**9+7) tmp = 500000004 ans = (ans*tmp) % (10**9+7) print(ans)
p02572
N = int(eval(input())) A = list(map(int, input().split())) s, t = 0, 0 for i in range(N): s += A[i] t += A[i]**2 s = s**2 ans = (s-t) % (10**9+7) # tmp = (2**1000000005) % (10**9+7) tmp = 500000004 ans = (ans*tmp) % (10**9+7) print(ans)
N = int(eval(input())) A = list(map(int, input().split())) s, t = 0, 0 for i in range(N): s += A[i] t += A[i]**2 s = s**2 # 割り算のmodを求めるため、逆元を求め、積に変換する ans = (s-t) % (10**9+7) # tmp = (2**1000000005) % (10**9+7) tmp = 500000004 ans = (ans*tmp) % (10**9+7) print(ans)
p02572
MOD = 10**9 + 7 def main(): N = int(eval(input())) A = [int(i) for i in input().split()] from itertools import accumulate S = list(accumulate([0] + A)) ans = 0 for i in range(N-1): ans += A[i] * (S[N] - S[i+1]) ans %= MOD print(ans) if __name__ == '__main__': main()
MOD = 10**9 + 7 def main(): _ = int(eval(input())) A = [int(i) for i in input().split()] ans = (sum(A)**2) % MOD - (sum(pow(a, 2, MOD) for a in A)) % MOD ans *= pow(2, MOD-2, MOD) ans %= MOD print(ans) if __name__ == '__main__': main()
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] ans %= int(1e9+7) print(ans)
n = int(eval(input())) a = list(map(int,input().split())) ans = 0 latsum = sum(a)-a[0] for i in range(n-1): ans += a[i]*latsum ans %= int(1e9+7) latsum -= a[i+1] print(ans)
p02572
N = int(eval(input())) An_input = input().split() An = [int(s) for s in An_input] #print(An) A = An[0] + An[1] #print(A) cnt = 0 M = 10**9 + 7 for i in range(0, N-1): #print(i) for l in range(1, N-i): cnt += An[i] * An[i+l] #print(An[i], An[i+l]) #print(cnt) ans = cnt % M print(ans)
N = int(eval(input())) An_input = input().split() An = [int(s) for s in An_input] cnt = 0 k = 0 M = 10**9 + 7 for i in range(0, N-1): k += An[i] cnt += k * An[i+1] ans = cnt % M print(ans)
p02572
import itertools n = int(eval(input())) a = list(map(int, input().split())) mod_const = 1000000007 ans = 0 for i, j in list(itertools.combinations(a, 2)): ans += (i * j) if (ans >= mod_const): ans %= mod_const print(ans)
mod_const = 1000000007 n = int(eval(input())) a = list([int(x)%mod_const for x in input().split()]) ans = 0 for i in range(n): for j in range(n): if (j >= i): continue ans += (a[i] * a[j]) % mod_const print((ans % mod_const))
p02572
import sys import itertools def resolve(in_): N = int(next(in_)) A = list(map(int, next(in_).split())) mod = 10 ** 9 + 7 ans = 0 for i, a in enumerate(A): v = sum(A[i + 1:]) ans += a * v ans %= mod return ans def main(): answer = resolve(sys.stdin.buffer) print(answer) if __name__ == '__main__': main()
import sys def resolve(in_): N = int(next(in_)) A = tuple(map(int, next(in_).split())) mod = 10 ** 9 + 7 ans = 0 v = sum(A) for a in A: v -= a ans += a * v ans %= mod return ans def main(): answer = resolve(sys.stdin.buffer) print(answer) if __name__ == '__main__': main()
p02572
N = int(eval(input())) A = list(map(int,input().split())) S = [0 for i in range(N-1)] for i in range(N-1): K = sum(A[i+1:]) S[i] = A[i]*K ans = sum(S)%(10**9+7) print(ans)
N = int(eval(input())) A = list(map(int,input().split())) K = sum(A) S = 0 for i in range(N-1): K = K - A[i] S = S + A[i]*K ans = S%(10**9+7) print(ans)
p02572
N, *A = list(map(int, open(0).read().split())) MOD = 1000000007 ans = 0 for i in range(N-1): for j in range(i+1, N): ans += (A[i] % MOD) * (A[j] % MOD) ans %= MOD print(ans)
from itertools import accumulate MOD = 10 ** 9 + 7 N, *A = list(map(int, open(0).read().split())) B = list(accumulate(A)) # cumsum ans = 0 for i in range(N-1): ans += A[i] * (B[-1] - B[i]) % MOD ans %= MOD print(ans)
p02572
def main(): n = int(eval(input())) a = list(map(int,input().split())) import collections c = collections.Counter(a).most_common() m = 10**9 + 7 ans = 0 for i in range(0,len(c)): num1 = c[i][0] cnt1 = c[i][1] if cnt1 != 1: tmp = (num1**2) % m ans += tmp * ((cnt1 * (cnt1 - 1) ) // 2) for j in range(i+1, len(c)): num2 = c[j][0] cnt2 = c[j][1] tmp = (num1 * num2) % m ans += tmp * (cnt1 * cnt2) print((ans%m)) if __name__=='__main__': main()
def main(): n = int(eval(input())) a = list(map(int,input().split())) m = 10**9 + 7 ans = 0 s = [] total = sum(a) s.append(total-a[0]) for i in range(1,n): s.append(s[i-1] - a[i]) for i in range(n): tmp = s[i] % m ans += tmp * a[i] # ans //= 2 print((ans%m)) if __name__=='__main__': main()
p02572
N = int(eval(input())) a = list(map(int,input().split())) mod = pow(10,9)+7 s = 0 for i in range(N-1): b = a[i] for j in range(i+1,N): s += b*a[j] s %= mod print(s)
N = int(eval(input())) a = list(map(int,input().split())) a_s = sum(a) mod = 10**9+7 s = 0 for i in range(N-1): b = a[i] a_s -= b s += b*(a_s) s %= mod print(s)
p02572
from itertools import product n = int(eval(input())) arr = list(map(int, input().split())) sum_arr = 0 list1 = list(product(arr, repeat = 2)) for (k, v) in list1: sum_arr = sum_arr + (k*v) for value in arr: sum_arr = sum_arr - (value*value) ans = int(sum_arr/2) print((ans%1000000007))
n = int(eval(input())) s = list(map(int, input().split())) sum1 = sum(s) sum2 = 0 for i in range(n): sum2 = sum2 + (sum1 - sum(s[:i+1]))*s[i] print((sum2%1000000007))
p02572
N = int(eval(input())) A = list(map(int, input().split())) MOD = 10**9 + 7 ans = 0 for i in range(1, N): for j in range(i+1, N+1): # print("{}:{}".format(i, j)) ans += A[i-1] * A[j-1] ans %= MOD print(ans)
N = int(eval(input())) A = list(map(int, input().split())) MOD = 10 ** 9 + 7 ans = 0 s = sum(A) for a in A: s -= a ans += s * a ans %= MOD print(ans)
p02572
nn = int(eval(input())) aa = list(map(int, input().split())) bb = [0]*(nn-1) mysum = sum(aa) % (10**9 + 7) mydiff = 0 for i in range(1,nn): mydiff += aa[i - 1] tete = mysum - mydiff if tete >= 0: bb[i-1] = tete else: bb[i-1] = tete + 10**9+7 finalsum = 0 for i in range(nn-1): finalsum += aa[i]*bb[i] finalsum = finalsum % (10**9 + 7) print(finalsum)
nn = int(eval(input())) aa = list(map(int, input().split())) bb = [0]*(nn-1) mysum = 0 for i in range(nn): mysum += aa[i] % (10**9 + 7) mydiff = 0 for i in range(1,nn): mydiff += aa[i - 1] tete = mysum - mydiff if tete >= 0: bb[i-1] = tete else: bb[i-1] = tete + 10**9+7 finalsum = 0 for i in range(nn-1): finalsum += aa[i]*bb[i] finalsum = finalsum % (10**9 + 7) print(finalsum)
p02572
N = int(eval(input())) A = list(map(int, input().split())) sum_ = 0 for i in range(N): for j in range(i + 1, N): sum_ += A[i] * A[j] sum_ %= 1_000_000_007 print(sum_)
N = int(eval(input())) A = list(map(int, input().split())) tmp = sum(A) sum_ = 0 for a in A: tmp -= a sum_ += a * tmp print((sum_ % (1_000_000_007)))
p02572
MOD = 10**9 + 7 N = int(eval(input())) arr = list(map(int, input().split())) check = [0]*N check[0] = arr[0] check2 = [sum(arr)]*N ans = 0 for i in range(N-1): check[i+1] = check[i]+arr[i+1] for i in range(N): check2[i] -= check[i] for i in range(N-1): ans += check2[i]*arr[i] ans %= MOD print(ans)
MOD = 10**9 + 7 N = int(eval(input())) arr = list(map(int, input().split())) check = [sum(arr)]*N ans = 0 tmp = 0 for i in range(N-1): tmp += arr[i] check[i] -= tmp for i in range(N-1): ans += check[i]*arr[i] ans %= MOD print(ans)
p02572
import itertools N = int(eval(input())) a = list(map(int,input().split())) l = list(itertools.combinations(a,2)) ans = 0 for i in l: ans += i[0]*i[1] print((ans%(10**9 + 7)))
N = int(eval(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
n = int(eval(input())) a = list(map(int, input().split())) mod = 1000000007 res = 0 a_sum = sum(a) for i in range(n - 1): main = a.pop(0) a_sum = a_sum - main res = (res + main * a_sum % mod) % mod print(res)
n = int(eval(input())) a = list(map(int, input().split())) mod = 1000000007 res = 0 a_sum = sum(a) for i in range(n - 1): main = a[i] a_sum = a_sum - main res = (res + main * a_sum % mod) % mod print(res)
p02572
#k = int(input()) #s = input() #a, b = map(int, input().split()) #s, t = map(str, input().split()) #l = list(map(int, input().split())) #l = [list(map(int,input().split())) for i in range(n)] #a = [input() for _ in range(n)] import itertools n = int(eval(input())) seq = list(map(int, input().split())) ans = 0 a = list(itertools.combinations(seq,2)) for i in range(len(a)): #print(a[i][0], a[i][1]) ans += a[i][0] * a[i][1] ans %= 10**9+7 print(ans)
#k = int(input()) #s = input() #a, b = map(int, input().split()) #s, t = map(str, input().split()) #l = list(map(int, input().split())) #l = [list(map(int,input().split())) for i in range(n)] #a = [input() for _ in range(n)] N = int(eval(input())) seq = list(map(int, input().split())) ans = 0 for i in range(N -1): for j in range(i+1, N): tmp = (seq[i] * seq[j]) ans += tmp print((ans%(10**9+7)))
p02572
#k = int(input()) #s = input() #a, b = map(int, input().split()) #s, t = map(str, input().split()) #l = list(map(int, input().split())) #l = [list(map(int,input().split())) for i in range(n)] #a = [input() for _ in range(n)] N = int(eval(input())) seq = list(map(int, input().split())) ans = 0 for i in range(N -1): for j in range(i+1, N): tmp = (seq[i] * seq[j]) ans += tmp print((ans%(10**9+7)))
#k = int(input()) #s = input() #a, b = map(int, input().split()) #s, t = map(str, input().split()) #l = list(map(int, input().split())) #l = [list(map(int,input().split())) for i in range(n)] #a = [input() for _ in range(n)] N = int(eval(input())) seq = list(map(int, input().split())) s = 0 for i in range(N): s += seq[i] s2 =0 for i in range(N): s2 += seq[i]**2 s0 = (s**2 -s2)//2 print((s0%(10**9+7)))
p02572
import itertools N = int(eval(input())) As = list(map(int, input().split())) MOD = 10 ** 9 + 7 S = 0 for c in list(itertools.combinations(As, 2)): S += c[0] * c[1] % MOD print((S % MOD))
# import itertools N = int(eval(input())) As = list(map(int, input().split())) MOD = 10 ** 9 + 7 S = 0 # for c in list(itertools.combinations(As, 2)): # S += c[0] * c[1] % MOD for i in range(N): for k in range(i+1, N): S += As[i] * As[k] % MOD print((S % MOD))
p02572
n = int(eval(input())) l = list(map(int,input().split())) ans=0 for i in range(n): for j in range(i+1,n): ans += l[i]*l[j] print((ans%(10**9 + 7)))
n = int(eval(input())) l = list(map(int,input().split())) totalsqr = (sum(l))**2 individualsqrsum=0 for i in l: individualsqrsum += i**2 ans = (totalsqr - individualsqrsum) // 2 ans = ans%(10**9 + 7) print(ans)
p02572
N = int(eval(input())) A = list(map(int, input().split())) ans = 0 MOD = 10**9 + 7 kake = 0 for i in range(N): kake = A[i] tasu = 0 for j in range(i+1, N): tasu += A[j] ans = (ans + kake*tasu)%MOD print(ans)
N = int(eval(input())) A = list(map(int, input().split())) + [0] B = [0]*(N+1) for i in range(N-1): B[N-i-1] = A[N-i-1]+B[N-i] ans = 0 MOD = 10**9 + 7 for i in range(N-1): ans = (ans + A[i]*B[i+1])%MOD print(ans)
p02572
import itertools N=int(eval(input())) A=list(map(int,input().split())) c=list(itertools.combinations(A,2)) p = 10**9 + 7 ans=0 for i in c: ans+= (i[0]*i[1])%p print((ans%p))
N=int(eval(input())) A=list(map(int,input().split())) ans=0 p= 10**9 +7 for i in range(N): ans += (A[i]*(sum(A[i+1:])))%p print((ans%p))
p02572
N=int(eval(input())) A=list(map(int,input().split())) ans=0 p= 10**9 +7 for i in range(N): ans += (A[i]*(sum(A[i+1:])))%p print((ans%p))
N=int(eval(input())) A=list(map(int,input().split())) ans=0 S=sum(A) p= 10**9 +7 for i in range(N): S-=A[i] ans += (A[i]*S)%p print((ans%p))
p02572
#d,t,s=map(int,input().split()) n=int(eval(input())) A=list(map(int,input().split())) ans=0 r=10**9+7 for i in range(n): for j in range(i+1,n): ans+=(A[i]*A[j])%r ans%=r print(ans)
import itertools #h,w=map(int,input().split()) #S=[list(map(int,input().split())) for _ in range(h)] n=int(eval(input())) A=list(map(int,input().split())) Ar=list(itertools.accumulate(A)) ans=0 for i in range(n-1): ans+=A[i]*(Ar[n-1]-Ar[i]) ans%=10**9+7 print(ans)
p02572
N = int(eval(input())) A = list(map(int,input().split())) sum = 0 for i in range(N-1): for j in range(i+1,N): sum = (sum+ A[i]*A[j])%(10**9+7) print(sum)
N = int(eval(input())) A = list(map(int,input().split())) a = 0 s = 0 for i in range(N): a = (a+A[i])%(10**9+7) for i in range(N-1): a = a-A[i] s = (s+A[i]*a)%(10**9+7) print(s)
p02572
N = int(eval(input())) A = list(input().split()) B = [int(a) for a in A] x = 10**9+7 summation = sum((B[i] * (sum(B[j] for j in range(i+1,N)))) for i in range(N-1)) % x print(summation)
N = int(eval(input())) A = list(input().split()) B = [int(a) for a in A] x = 10**9+7 summation1 = sum(B) ** 2 summation2 = sum(b ** 2 for b in B) summation = ((summation1 - summation2) // 2) % x print(summation)
p02572
MOD = 10**9 + 7 n = int(eval(input())) a = list(map(int, input().split())) ans, rem = 0, 0 for i in range(n - 1): rem += a[n - 1 - i] % MOD ans += a[n - 2 - i] * rem % MOD print((ans % MOD))
MOD = 10**9 + 7 n = int(eval(input())) a = list(map(int, input().split())) ans, s = 0, sum(a) % MOD for i in range(n - 1): s -= a[i] % MOD ans += a[i] * s % MOD print((ans % MOD))
p02572
from itertools import accumulate m = 1000000007 N, *A = list(map(int, open(0).read().split())) result = 0 b = list(accumulate(A)) for i in range(N): result += A[i] * (b[N - 1] - b[i]) result %= m print(result)
m = 1000000007 N, *A = list(map(int, open(0).read().split())) result = 0 a = 0 for i in range(1, N + 1): result += a * A[N - i] a += A[N - i] result %= m print(result)
p02572
N = int(eval(input())) A = list(map(int, input().split())) mod = 10 ** 9 + 7 ans = 0 for i in range(N): for j in range(i + 1, N): ans += (A[i] * A[j]) print((ans % mod))
N = int(eval(input())) A = list(map(int, input().split())) mod = 10 ** 9 + 7 su = 0 a = 0 for i in range(N-1,-1,-1): su+= A[i] * a a += A[i] print((su % mod))
p02572
N = int(eval(input())) A = list(map(int, input().split())) mod = 10 ** 9 + 7 su = 0 a = 0 for i in range(N-1,-1,-1): su+= (A[i] * a) % mod a += A[i] print((su % mod))
N = int(eval(input())) A = list(map(int, input().split())) mod = 10 ** 9 + 7 B = list([x ** 2 for x in A]) SA = sum(A) SB = sum(B) print((((SA * SA - SB) // 2) % mod))
p02572
mod = 1000000007 n = int(eval(input())) a = list(map(int,input().split())) import itertools b = list(itertools.combinations(a, 2)) #print(b) for i in range(len(b)): b[i] = (b[i][0]*b[i][1])%mod print((sum(b)%mod))
mod = 1000000007 n = int(eval(input())) a = list(map(int,input().split())) ans = 0 s = sum(a) for i in range(n-1): b = (s-sum(a[:i+1]))%mod ans += (a[i]*(b))%mod print((ans%mod))
p02572
mod = 1000000007 n = int(eval(input())) a = list(map(int,input().split())) ans = 0 s = sum(a) for i in range(n-1): b = (s-sum(a[:i+1]))%mod ans += (a[i]*(b))%mod print((ans%mod))
mod = 1000000007 n = int(eval(input())) a = list(map(int,input().split())) ans = 0 b = sum(a) for i in range(n-1): b = b-a[i] ans += (a[i]*(b))%mod print((ans%mod))
p02572
n = int(eval(input())) a = list(map(int, input().split())) m = (10**9 + 7) result = 0 for i in range(n): x = a[i] if abs(x-m) < x: x -= m y = 0 for j in range(i+1, n): y = (y + a[j]) % m result = (result + (x*y)) % m if(result < 0): result += m print(result)
n = int(eval(input())) a = list(map(int, input().split())) m = (10**9 + 7) result = 0 sum_a = 0 for i in range(n): sum_a = (sum_a + a[i]) % m result = 0 for i in range(n): x = a[i] sum_a -= x result = (result + x*sum_a) % m if(result < 0): result += m print(result)
p02572
import itertools k = 10 ** 9 + 7 N = int(eval(input())) L = list(map(int, input().split())) S = 0 for c in itertools.combinations(L, 2): S += (c[0] * c[1]) % k print((S % k))
k = 10 ** 9 + 7 N = int(eval(input())) L = list(map(int, input().split())) S = sum(L) ** 2 for i in L: S -= i ** 2 print(( (S // 2) % k))
p02572
n = int(eval(input())) A = list(map(int, input().split())) ans = 0 mod = 10**9 + 7 for i in range(n): for j in range(i+1, n): ans += A[i]*A[j] print((ans%mod))
n = int(eval(input())) A = list(map(int, input().split())) ans = 0 mod = 10**9 + 7 s = sum(A) for a in A: s -= a ans += a * s print((ans%mod))
p02572
#abc177_C_5_あまりの計算を挟むのは、その計算の対象になるときだけ int_n = int(eval(input())) list_tmp = list(map(int, input().split())) int_sum = 0 int_divide = (10**9) + 7 for i in range(0, len(list_tmp) - 1): for j in range(i + 1, len(list_tmp)): if list_tmp[i] >= int_divide: list_tmp_i = list_tmp[i]%int_divide else: list_tmp_i = list_tmp[i] if list_tmp[j] >= int_divide: list_tmp_j = list_tmp[j]%int_divide else: list_tmp_j = list_tmp[j] int_sum = int_sum + (list_tmp_i*list_tmp_j) if int_sum >= int_divide: int_sum = int_sum%int_divide print(int_sum)
#abc177_C_6_retry_累積和を使用する int_n = int(eval(input())) list_tmp = list(map(int, input().split())) int_sum = 0 int_divide = (10**9) + 7 int_sum_tmp = sum(list_tmp) for i in range(0, len(list_tmp) - 1): int_sum_tmp = int_sum_tmp - list_tmp[i] int_sum = int_sum + (int_sum_tmp * list_tmp[i]) print((int_sum % int_divide)) # for j in range(i + 1, len(list_tmp)): # if list_tmp[i] >= int_divide: # list_tmp_i = list_tmp[i]%int_divide # else: # list_tmp_i = list_tmp[i] # # if list_tmp[j] >= int_divide: # list_tmp_j = list_tmp[j]%int_divide # else: # list_tmp_j = list_tmp[j] # # int_sum = int_sum + (list_tmp_i*list_tmp_j) # # if int_sum >= int_divide: # int_sum = int_sum%int_divide # #print(int_sum)
p02572
n = int(eval(input())) a = list(map(int, input().split())) mod = 1000000007 ans = 0 for i in range(n-1): for j in range(i+1, n): ans += a[i] * a[j] ans %= mod print(ans)
n = int(eval(input())) a = list(map(int, input().split())) mod = 1000000007 s = sum(a) % mod ans = 0 for i in a: s -= i ans += s * i ans %= mod print(ans)
p02572
def main(): n = int(eval(input())) a_list = list(map(int, input().split())) mod = 10 ** 9 + 7 sum_a = sum(a_list) ans = 0 for i in range(n - 1): sum_a -= a_list[i] ans += (a_list[i] * sum_a) % mod print((ans % mod)) if __name__ == "__main__": main()
def main(): n = int(eval(input())) a_list = list(map(int, input().split())) mod = 10 ** 9 + 7 x = 0 ans = 0 for i in range(1, n): x = (x + a_list[i - 1]) % mod ans = (ans + a_list[i] * x) % mod print(ans) if __name__ == "__main__": main()
p02572
n = int(eval(input())) a = list(map(int,input().split())) max = (10 ** 9) + 7 sum = 0 for i in range (n-1): for j in range (n): if i > j: continue if i != j: sum += a[i]*a[j] if sum > max: sum = sum % max print(sum)
n = int(eval(input())) a = list(map(int,input().split())) max = (10 ** 9) + 7 #一列の総和 wa = 0 for i in range (n): wa += a[i] #a11, a22, ...の総和 rem = 0 for i in range(n): rem += a[i]*a[i] sum = ((wa*wa) - rem) // 2 ans = sum % max print(ans)
p02572
n = int(eval(input())) a = list(map(int,input().split())) max = (10 ** 9) + 7 #一列の総和 wa = 0 for i in range (n): wa += a[i] #a11, a22, ...の総和 rem = 0 for i in range(n): rem += a[i]*a[i] sum = ((wa*wa) - rem) // 2 ans = sum % max print(ans)
n = int(eval(input())) a = list(map(int,input().split())) max = (10 ** 9) + 7 #入力配列の総和 line = 0 for i in range (n): line += a[i] #a11, a22, ...対角線要素の総和 rem = 0 for i in range(n): rem += a[i]*a[i] sum = ((line*line) - rem) // 2 ans = sum % max print(ans)
p02572
MOD = 1000000007 N = int(eval(input())) A = list(map(int, input().split())) ans = 0 B = [0]*(N-1) for i in range(1, N): B[i-1] = sum(A[i:N]) for i in range(0, N-1): ans += A[i] * B[i] ans %= MOD print(ans)
MOD = 1000000007 N = int(eval(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
N = int(eval(input())) A = list(map(int, input().split())) ans = 0 for i in range(1, N): ans += A[i - 1] * sum(A[i:]) print((ans % (10**9 + 7)))
N = int(eval(input())) A = list(map(int, input().split())) mod = 10**9 + 7 s = sum(A) % mod ans = 0 for i in range(N): s -= A[i] if 0 > s: s += mod ans += A[i] * s ans %= mod print(ans)
p02572
N = int(eval(input())) A = list(map(int, input().split())) mod = 10**9 + 7 s = sum(A) % mod ans = 0 for i in range(N): s -= A[i] if 0 > s: s += mod ans += A[i] * s ans %= mod print(ans)
N = int(eval(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 ans %= mod print(ans)
p02572
n=int(eval(input())) x = list(map(int, input().split())) ans=0 total=0 for i in range(n): l=i+1 for l in range(i+1,n): ans=ans+x[l] total=total+x[i]*ans ans=0 print((total %1000000007))
n=int(eval(input())) x = list(map(int, input().split())) ans=0 total=0 t=sum(x) for i in range(n): t=t-x[i] total=total+x[i]*(t) print((total %1000000007))
p02572
def resolve(): n = int(eval(input())) a = list(map(int, input().split())) ans = 0 num = (10 ** 9) + 7 for i in range(n): tmp = 0 for j in range(i+1, n): tmp = (a[i] * a[j]) % num ans += tmp ans = int(ans % num) print(ans) resolve()
def resolve(): n = int(eval(input())) a = list(map(int, input().split())) ans = 0 mod = (10 ** 9) + 7 csum = sum(a) for i in range(n): csum -= a[i] ans += a[i] * csum ans = int(ans % mod) print(ans) resolve()
p02572
N = int(eval(input())) A = list(map(int, input().split())) m = 10 ** 9 + 7 def Calc(a: int, b: int) -> int: return (a * b) % m ans = 0 for i in range(N): for j in range(i + 1, N): ans += Calc(A[i], A[j]) ans = ans % m print(ans)
N = int(eval(input())) A = list(map(int, input().split())) m = 10 ** 9 + 7 total = [0] * (N + 1) for i in range(N): total[i + 1] = total[i] + A[i] total_rev = [0] * (N + 1) for i in range(N): total_rev[i] = total[N] - total[i] ans = 0 for i in range(N - 1): ans = (ans + A[i] * total_rev[i + 1]) % m print(ans)
p02572
N = int(eval(input())) A = list(map(int, input().split())) ans = 0 MOD = 10 ** 9 + 7 for i in range(N - 1): tmp = sum(A[0: i + 1]) * A[i + 1] ans += (tmp % MOD) print((ans % MOD))
N = int(eval(input())) A = list(map(int, input().split())) ans = 0 MOD = 10 ** 9 + 7 s = 0 for i in range(N - 1): s += A[i] tmp = s * A[i + 1] ans += (tmp % MOD) print((ans % MOD))
p02572
n = int(eval(input())) L = list(map(int,input().split())) total = 0 for i in range(n-1): for j in range(i+1,n): total += L[i]*L[j] print((total % (10**9+7)))
n = int(eval(input())) L = list(map(int,input().split())) mod = 1000000007 ans = 0 x = 0 for i in range(n): ans = (ans + L[i]*x)%mod x = (x + L[i]%mod) print(ans)
p02572
N = int(eval(input())) A = list(map(int, input().split())) sum = 0 for i in range(N): for j in range(i+1, N): sum = sum + A[i]*A[j] if (sum > 10**9 + 7): sum = sum % (10**9 + 7) print(sum)
N = int(eval(input())) A = list(map(int, input().split())) MOD = 10**9 + 7 sum_A = 0 for i in range(N): sum_A = (sum_A + A[i]) % MOD sum = 0 for i in range(N): sum_A = (sum_A - A[i]) % MOD sum = (sum + sum_A*A[i]) % MOD print(sum)
p02572
N = int(eval(input())) As = list(map(int, input().split())) ans = 0 for i in range(N): for j in range(N-i-1): ans += As[i]*As[j+i+1] if ans >= 10**9+7: ans = ans%(10**9+7) print(ans)
N = int(eval(input())) As = list(map(int, input().split())) sum = 0 for i in range(N): sum += As[i] sum %= 10**9+7 ans = 0 for i in range(N): sum -= As[i] ans += As[i]*sum ans %= 10**9+7 print(ans)
p02572
n=int(eval(input())) a=list(map(int,input().split())) ans=0 for i in range(n): for j in range(i+1,n): ans=(ans+a[i]*a[j])%(10**9+7) print(ans)
n=int(eval(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
N = int(eval(input())) A = list(map(int, input().split())) wa = 0 for i in range(N-1): i_wa = 0 for m in A[i+1:]: i_wa += m wa += A[i] * i_wa print((wa % (10**9+7)))
N = int(eval(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
import sys input = sys.stdin.readline #n = int(input()) #l = list(map(int, input().split())) ''' a=[] b=[] for i in range(): A, B = map(int, input().split()) a.append(A) b.append(B)''' 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] if ans>10**9+7: ans%=10**9+7 print(ans)
import sys input = sys.stdin.readline #n = int(input()) #l = list(map(int, input().split())) ''' a=[] b=[] for i in range(): A, B = map(int, input().split()) a.append(A) b.append(B)''' n=int(eval(input())) a=list(map(int, input().split())) ans=0 anss=[0]*(n+1) for i in range(1,n+1): anss[-i-1]=anss[-i]+a[-i] if anss[-i-1]>10**9+7: anss[-i-1]%=10**9+7 #print(anss) for i in range(n-1): ans+=a[i]*anss[i+1] if ans>10**9+7: ans%=10**9+7 print(ans)
p02572
n = int(eval(input())) a = list(map(int, input().split())) ans = 0 mod = 10**9 + 7 for i in range(n): ans += (a[i] * sum(a[i+1:])) print((ans%mod))
n = int(eval(input())) a = list(map(int, input().split())) sum_a = sum(a) ans = 0 mod = 10**9 + 7 for i in range(n): sum_a -= a[i] ans += a[i] * sum_a ans %= mod print(ans)
p02572
n=int(eval(input())) lst=list(map(int,input().split())) total=0 for i in range(n): temp=0 for j in range(i+1, n): temp+=lst[j] total+=lst[i]*temp print((total%(10**9+7)))
n=int(eval(input())) lst=list(map(int,input().split())) total=0 temp=0 for i in range(1, n): temp+=lst[i] for j in range(n-1): total+=lst[j]*temp temp-=lst[j+1] print((total%(10**9+7)))
p02572
def s():return int(eval(input())) def mp():return list(map(int,input().split())) # a =s() # b =s() # ans = "" # for i in range(len(b)): # ans+=b[i] # if ans in a: # pass # else: # print(len(b)-i) # break a = s() b = list(mp()) ans=0 for i in range(a): for j in range(i+1,a): ans+=b[i]*b[j] ans%=((10**9)+7) print(ans)
def s():return int(eval(input())) def mp():return list(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
N = int(eval(input())) A = list(map(int,input().split())) pro = [] for i in range(N-1): redi = 0 for j in range(i+1,N): redi += (A[i] * A[j])%(1000000007) pro.append(redi) red = sum(pro) res = red%(1000000007) print(res)
N = int(eval(input())) A = list(map(int,input().split())) sumA = sum(A)%(1000000007) sumA2 = (sumA * sumA)%(1000000007) square = 0 for i in range(N): square += ( A[i]**2 ) % (1000000007) square = square % (1000000007) buf = sumA2 - square if buf < 0: buf = buf + (1000000007) res = ( buf * ((1000000007+1)//2)) % 1000000007 print((int(res)))
p02572
def main(): N = int(eval(input())) A = list(map(int, input().split())) sum = 0 for i in range(0, N - 1): for j in range(i + 1, N): sum += (A[i] * A[j]) sum = sum % (10 ** 9 + 7) print(sum) if __name__ == "__main__": main()
def main(): N = int(eval(input())) A = list(map(int, input().split())) B = sum(A) answer = 0 for i in range(0, N): answer += A[i] * (B - A[i]) B -= A[i] answer %= (10 ** 9 + 7) print(answer) if __name__ == "__main__": main() # A1*A2 + A1*A3 + ... + A1*AN = A1 * (A2 + A3 + ... + AN) # + # A2*A3 + A2*A4 + ... +| A2*AN = A2 * (A3 + A4 + ... + AN)
p02572
n = int(eval(input())) a = [int(i) for i in input().split()] ans = 0 for i in range(n): ans += (a[i]*sum(a[i+1:])) ans = ans % (10**9+7) print(ans)
n = int(eval(input())) a = [int(i) for i in input().split()] ans = 0 b = sum(a) for i in range(n): b -= a[i] ans += (a[i]*b) ans = ans % (10**9+7) print(ans)
p02572
n = int(eval(input())) a = list(map(int,input().split())) ans = 0 mod = 10**9 + 7 num = a[0] for i in range(n-1): cnt = sum(a) - num cnt %= mod ans += a[i]*cnt ans %= mod num += a[i+1] num %= mod print((ans%mod))
n = int(eval(input())) a = list(map(int,input().split())) ans = 0 mod = 10**9 + 7 num = sum(a)%mod for i in range(n-1): num -= a[i] num %= mod ans += a[i]*num ans %= mod 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] ans = ans % 1000000007 print(ans)
N = int(eval(input())) A = list(map(int,input().split())) ans =0 sum = sum(A) for i in range(N-1): sum-=A[i] ans+=A[i]*sum ans = ans % 1000000007 print(ans)
p02572
m = int(eval(input())) a = list(map(int, input().split())) mod = 10**9 + 7 ans = 0 for x in range(m-1): if a[x] % mod != 0: tmp = sum(a[x+1:m]) ans += a[x] * tmp print((ans%mod))
m = int(eval(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
def resolve(): n = int(eval(input())) a = tuple(map(int,input().split())) N = 10**9+7 ans = 0 for i in range(n): for j in range(i+1,n): ans += a[i]*a[j] ans %= N print(ans) resolve()
def resolve(): n = int(eval(input())) a = tuple(map(int,input().split())) N = 10**9+7 s = sum(a) % N ans = 0 for i in a: s -= i ans += s*i ans %= N print(ans) resolve()
p02572
n = int(eval(input())) a = list(map(int,input().split())) s = 0 m=10**9+7 for i in range(n-1): ss=0 for j in range(i+1,n): ss+=a[j] ss=ss%m s+=(a[i]*ss)%m print((s%m))
n = int(eval(input())) mod = 1000000007 a = list(map(int,input().split())) width = 0 ans = 0 for i in range(n): ans = (ans + a[i]*width) % mod width = (width + a[i]) % mod print(ans)
p02572
n = int(eval(input())) a = list(map(int, input().split())) ans = 0 big = pow(10,9) + 7 for i in range(n-1): for j in range(i+1,n): ans += a[i] * a[j] ans %= big print(ans)
n = int(eval(input())) a = list(map(int, input().split())) big = pow(10,9) + 7 sums = pow(sum(a),2) a_2 = list([x ** 2 for x in a]) print((((sums-sum(a_2)) // 2)%big))
p02572
N = int(eval(input())) A = list(map(int, input().split())) #print(A) total = 0 for i in range(N): #print(i, A[i]) sum = 0 start = i + 1 for j in range(start, N): #print(i, j) sum = sum + A[j] #print(A[i], sum) total = (total + A[i] * sum) % 1000000007 print(total)
N = int(eval(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
n = int(eval(input())) a = [int(x) for x in input().split()] ans = 0 for i in range(n-1): for j in range(i+1,n): ans += a[i]*a[j] print((ans%(10**9+7)))
n = int(eval(input())) a = [int(x) for x in input().split()] sum = 0 ans = 0 for e in a: sum += e for e in a: sum -= e ans += e*sum print((ans%(10**9+7)))
p02572
N = int(eval(input())) A = list(map(int, input().split())) ans = 0 for i in range(N): for j in range(i+1, N): ans += A[i] * A[j] ans = ans % (10 ** 9 + 7) print(ans)
N = int(eval(input())) A = list(map(int, input().split())) ans = 0 tmp = sum(A) for i in range(N): tmp -= A[i] ans += A[i] * tmp ans = ans % (10 ** 9 + 7) print(ans)
p02572
import itertools N = int(eval(input())) A = list(map(int,input().split())) A_comb = list(itertools.combinations(A,2)) tot = 0 for i,j in A_comb: cnt = (i*j)%(10**9+7) tot = (tot + cnt)%(10**9+7) print(tot)
N = int(eval(input())) A = list(map(int,input().split())) A_sum = sum(A[1:]) tot = 0 for i in range(N-1): tot += (A[i]*A_sum)%(10**9+7) tot = tot%(10**9+7) A_sum -= A[i+1] print(tot)
p02572
import itertools n = int(eval(input())) a_l = list(map(int, input().split())) ans = 0 for i in range(n - 1): for j in range(i + 1, n): v1 = a_l[i] v2 = a_l[j] ans += v1 * v2 ans = ans % (10 ** 9 + 7) print(ans)
n = int(eval(input())) a_list = input().split() a_list_reverse = a_list[::-1] # print(a_list_reverse) rusekiwa = [0] * (len(a_list_reverse) - 1) sum_v = 0 for i in range(len(a_list_reverse) - 1): sum_v += int(a_list_reverse[i]) rusekiwa[i] = sum_v # print(rusekiwa) ans = 0 for i in range(len(a_list) - 1): v = int(a_list[i]) * rusekiwa[-1 - (i)] # print(v) # v = v % (10 ** 9 + 7) ans += v ans = ans % (10 ** 9 + 7) # ans = ans % (10 ** 9 + 7) print(ans)
p02572
import itertools from heapq import heapify, heappop, heappush, heappushpop nCr = {} class PriorityQueue: def __init__(self, heap): ''' heap ... list ''' self.heap = heap heapify(self.heap) def push(self, item): heappush(self.heap, item) def pop(self): return heappop(self.heap) def pushpop(self, item): return heappushpop(self.heap, item) def __call__(self): return self.heap heap = [] # ヒープといっても順序を工夫したただのリスト q = PriorityQueue(heap) #ここでインスタンスを作ってます n = int(eval(input())) l = list(map(int, input().split())) mod = 1000000007 result = [] for i in range(len(l)): for j in range(i + 1, len(l)): result.append([l[i], l[j]]) for a,b in result: q.push(((a % mod) * (b % mod)) % mod) print((sum(heap) % mod))
n = int(eval(input())) l = list(map(int, input().split())) mod = 1000000007 q = sum(l) ans = 0 for i in range(len(l)): q -= l[i] ans += l[i] * q % mod print((ans % mod))
p02572
n = int(eval(input())) a = list(map(int,input().split())) ans = 0 for i in range(len(a)): for j in range(i+1,len(a)): ans += a[i]*a[j] print((ans%(10**9+7)))
n = int(eval(input())) a = list(map(int,input().split())) s = sum(a) aa = [a[i]*a[i] for i in range(n)] s2 = sum(aa) print(((s**2 - s2) //2%(10**9+7)))
p02572
n = int(eval(input())) A = list(map(int,input().split())) sum_a = 0 for i in range(n-1): for j in range(i+1,n): sum_a += (A[i] * A[j]) print((int(sum_a%(1e9 + 7))))
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 %(int(1e9 + 7)) print(ans)
p02572
n = int(eval(input())) a = list(map(int,input().split())) a.sort() b = 0 for i in range(n): for j in range(1,n - i): b += a[i]*a[i + j] b %= (10**9 + 7) print(b)
n = int(eval(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 ans %= mod print(ans)
p02572
N = int(eval(input())) al = list(map(int,input().split())) sss=0 for i in range(N): sss+=al[i]*sum(al[i+1:N]) print((sss%1000000007))
N = int(eval(input())) al = list(map(int,input().split())) sss=0 pss=0 for i in range(1,N): pss+=al[i-1] sss+=al[i]*pss print((sss%1000000007))
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 %= mod print(ans)
n = int(eval(input())) a = list(map(int, input().split())) mod = 10 ** 9 + 7 ans = 0 sum_a = sum(a) for i in range(n): sum_a -= a[i] ans += sum_a * a[i] ans %= mod print(ans)
p02572
n = int(eval(input())) a = list(map(int,input().split())) ans = 0 b = [] c = 0 for i in range(n-1,0,-1): c = c + a[i] b.insert(0,c) b.insert(0,0) for j in range(n-1): ans = (a[j] * b[j+1] + ans) % (10**9+7) print(ans)
n = int(eval(input())) a = list(map(int,input().split())) ans = 0 b = [0] * n c = 0 for i in range(n): c = c + a[i] b[i] = c for j in range(n-1): ans = (a[j] * (b[n-1] - b[j]) + ans) % (10**9+7) print(ans)
p02572
N=int(eval(input())) l=list(map(int,input().split())) k=[0]*N a=0 for i in range(N-1): a+=l[i] k[i]=(sum(l)-a)%(10**9+7) ans=0 for i in range(0,len(l)-1): ans=(ans+l[i]*k[i]%(10**9+7))%(10**9+7) print(ans)
N=int(eval(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
n=int(eval(input())) A=list(map(int,input().split())) MOD = 1000000007 B=0 for i in range(len(A)): B += (A[i]*sum(A[i+1:len(A)]))%MOD print((B%MOD))
n=int(eval(input())) A=list(map(int,input().split())) MOD = 1000000007 B=0 tem = sum(A) for i in range(len(A)): tem -= A[i] B+= (A[i]%MOD)*(tem%MOD) print((B%MOD))
p02572
N = int(eval(input())) A = list(map(int, input().split())) ans = 0 a = 7 + 10**9 for i in range(N-1): for j in range(i+1,N): ans += (A[i] * A[j]) % a print((ans % a))
N = int(eval(input())) A = list(map(int, input().split())) a = 0 ans = 0 mod = 10**9 + 7 for i in range(N-1): a += A[N-i-1] ans += A[N-i-2] * a print((ans%mod))
p02572
n = int(eval(input())) lst = list(map(int, input().split())) res = 0 for i in range(n): for j in range(i+1, n): res += lst[i] * lst[j] print((res % ((10**9)+7)))
n = int(eval(input())) lst = list(map(int, input().split())) ans = 0 summ = sum(lst) summ_sq = summ**2 for i in range(n): ans += lst[i]**2 res = (summ_sq-ans)//2 print((res % ((10**9)+7)))
p02572
n = int(eval(input())) a = list(map(int, input().split())) b = [0] * n b[-1]= a[-1] total = 0 mod = 10**9 + 7 for i in range(n-2, 0, -1): b[i] = a[i] + b[i + 1] for i in range(n-1): total = (total + (a[i] * b[i + 1]) % mod) % mod print(total)
n = int(eval(input())) a = list(map(int, input().split())) b = [0] * n b[-1]= a[-1] total = 0 mod = 10**9 + 7 cumsum = sum(a) for i in range(n-1): cumsum -= a[i] total = (total + (a[i] * cumsum) % mod) % mod print(total)
p02572
N = int(eval(input())) A = list(map(int,input().split())) MOD = 1000000007 ans = 0 for i in range(N): x = sum(A[i+1:]) % MOD y = (A[i] * x) % MOD ans += y ans %= MOD print(ans)
N = int(eval(input())) A = list(map(int,input().split())) MOD = 1000000007 x = sum(A) ans = 0 for i in range(N): x -= A[i] y = x % MOD z = (A[i] * y) % MOD ans += z ans %= MOD print(ans)
p02572
num = int(eval(input(""))) val = list(map(int,input().split())) val_sum = 0 mod = 10**9 + 7 for i in range(num): for j in range(i+1,num): val_sum = val_sum + val[i]*val[j] print((val_sum%mod))
num = int(eval(input(""))) val = list(map(int,input().split())) val_sum = sum(val) ans = 0 mod = 10**9 + 7 for i in range(num): val_sum = val_sum - val[i] ans = val[i] * val_sum + ans print((ans%mod))
p02572