problem_id stringclasses 100 values | submission_id stringlengths 10 10 | status stringclasses 2 values | code stringlengths 6 806 |
|---|---|---|---|
p02572 | s799200695 | Accepted | mod = 10**9+7
N = int(input())
A = list(map(int,input().split()))
AA = 0
for i in range(N):
AA += A[i]**2
AA %= mod
print((sum(A)**2-AA)*pow(2,mod-2,mod) % mod) |
p02572 | s029053784 | Accepted | mod = 10 ** 9 + 7
n = int(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 | s280373506 | Accepted | MOD = 1000000007
n, *a = map(int, open(0).read().split())
wa = a + [0]
for i in range(n-1, 0, -1):
wa[i-1] += wa[i]
ans = 0
for i in range(n):
ans += a[i] * wa[i+1]
ans %= MOD
print(ans) |
p02572 | s378459942 | Accepted | n = int(input())
A = list(map(int, input().split()))
MOD = 10 ** 9 + 7
res = 0
tmp = 0
for i in range(1, n):
tmp += A[i - 1]
res += A[i] * tmp
res %= MOD
print(res)
|
p02572 | s933251974 | Accepted | n=int(input())
a=list(map(int,input().split()))
s=sum(a[1:])
ans=0
for i in range(1,n):
ans+=a[i-1]*s
s-=a[i]
print(ans%(10**9+7))
|
p02572 | s156985429 | Accepted | N = int(input())
As = list(map(int, input().split()))
sA = sum(As) % (10 ** 9 + 7)
print((sA * sA - sum( (A * A % (10 ** 9 + 7) for A in As) ) ) * pow(2, -1, 10 ** 9 + 7) % (10 ** 9 + 7))
|
p02572 | s442595016 | Accepted | n = int(input())
v = [int(x) for x in input().split()]
suma, ans = sum(v), 0
for i in range(n - 1):
suma -= v[i];
ans += (suma * v[i])
print(ans % 1000000007)
|
p02572 | s688140485 | Accepted | n=int(input())
z=[int(x) for x in input().split(' ')]
s=sum(z)
md=1000000007
ans=0
for i in range(n):
s-=z[i]
ans+=s*z[i]
print(ans%md) |
p02572 | s212305963 | Accepted | n= int(input())
a= [int(i) for i in input().split()]
pref=[0]*n
m = 10**9+7
pref[0] = a[0]%m
for i in range(1,n):
pref[i] = (pref[i-1]+a[i])%m
m = 10**9+7
ans = 0
#print(pref)
for i in range(n-1):
ans+= (a[i]%m *((pref[n-1]-pref[i])%m))%m
ans = ans%m
print(ans) |
p02572 | s228576448 | Accepted | n = int(input())
a = list(map(int, input().split()))
ans = 0
mod = 10 ** 9 + 7
a_r = list(reversed(a))
sumlist = [a_r[0]]
for i in range(1,len(a)):
sumlist.append(sumlist[-1] + a_r[i])
sumlist.reverse()
sumlist = sumlist[1:]
for i in range(len(sumlist)):
ans += a[i] * sumlist[i]
print(ans%mod)
|
p02572 | s449089171 | Accepted | N=int(input())
A=[0]+[int(i) for i in input().split()]
S=[0]*(N+1)
MOD=10**9+7
for i in range(1,N+1):
S[i]=(S[i-1]+A[i])%MOD
ans=0
for i in range(2,N+1):
ans=(ans+A[i]*S[i-1])%MOD
print(ans)
|
p02572 | s074392441 | Accepted | n = int(input())
a = list(map(int,input().split()))
mod = 10**9+7
sum_a = sum(a)%mod
sum_a2 = sum_a**2%mod
for i in range(n):
sum_a2 -= (a[i]**2)%mod
sum_a2 %= mod
if sum_a2%2 == 0:
ans = sum_a2//2
else:
ans = ((sum_a2+mod)//2)%mod
print(ans) |
p02572 | s814737831 | Accepted | n,*l=map(int,open(0).read().split())
print((sum(l)**2-sum(i**2 for i in l))//2%(10**9+7)) |
p02572 | s819779809 | Accepted | n = int(input())
a = list(map(int,input().split()))
MOD=10**9+7
sum1=0
for i in range(n):
sum1+=a[i]
sum1%=MOD
sum1*=sum1
sum1%=MOD
sum2=0
for i in range(n):
sum2+=pow(a[i],2,MOD)
sum2%=MOD
t = sum1-sum2
if t<0:
t+=MOD
print((t)*pow(2,MOD-2,MOD)%MOD)
|
p02572 | s203955796 | Accepted | N = int(input())
A = list(map(int, input().split()))
ans = 0
mod = 10 ** 9 + 7
num = sum(A)
for a in A:
num -= a
ans += a * num
print(ans % mod) |
p02572 | s857946746 | Accepted | 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)
|
p02572 | s407166238 | Accepted |
def resolve():
MOD = 10 ** 9 + 7
N = int(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 | s972018430 | Accepted | n=input()
lst=list(map(int,input().split()))
m=sum(lst)%(10**9+7)
s=0
for i in lst:
s=(s+i*i)%(10**9+7)
a=(m*m-s)%(10**9+7)
if a%2:print(a//2+5*10**8+4)
else:print(a//2) |
p02572 | s756925654 | Accepted | n = int(input())
a = list(map(int,input().split()))
ans = 0
s = sum(a)
for i in range(n):
ans += (s-a[i]) * a[i]
print((ans//2)%1000000007) |
p02572 | s782996654 | Accepted | n=int(input())
A=list(map(int,input().split()))
s=0
m=10**9+7
for i in A:
s+=i
s%=m
ans=0
for i in range(n-1):
s-=A[i]
if s<0:
s+=m
ans+=(A[i]%m)*s
ans%=m
print(int(ans)) |
p02572 | s769619949 | Accepted | mod = 1000000007
n = int(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 | s739749319 | Accepted | n = int(input())
a = list(map(int,input().split()))
b = sum(a)
m = 10**9 + 7
ans = 0
for i in range(n):
b -= a[i]
ans += a[i]*b % m
ans %= m
print(ans) |
p02572 | s753886900 | Accepted | l = int(input())
num = input().split(' ')
num = [int(i) for i in num]
ans = 0
s = sum(num)
for i in range(l):
s -= num[i]
ans += num[i] * s
print(ans%(10**9+7)) |
p02572 | s628417079 | Accepted | N = int(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 | s757757847 | Accepted | n = int(input())
a = list(map(int, input().split()))
s = [0] * n
for i in range(1, n):
s[i] = s[i-1] + a[i-1]
ans = 0
for i in range(1, n):
ans += a[i] * s[i]
mod = 10**9 + 7
# for i in range(n-1):
# for j in range(i+1, n):
# ans += a[i]*a[j]
print(ans%mod)
|
p02572 | s908513493 | Accepted | n=int(input())
a=list(map(int,input().split()))
a.reverse()
l=[0]*n
l[0]=a[0]
for i in range(n-1):
l[i+1]=l[i]+a[i+1]
ans=0
mod=10**9+7
for j in range(1,n):
ans+=(a[j]*l[j-1])%mod
print(ans%mod) |
p02572 | s544445794 | Accepted | '''
Created on 2020/08/29
@author: harurun
'''
def main():
import itertools
import sys
pin=sys.stdin.readline
pout=sys.stdout.write
perr=sys.stderr.write
N=int(pin())
A=list(map(int,pin().split()))
mod=10**9+7
B=list(itertools.accumulate(A))
ans=0
for i in range(N-1):
ans+=A[i]*(B[N-1]-B[i])
print(ans%mod)
return
main() |
p02572 | s146824080 | Accepted | n = int(input())
a = list(map(int, input().split()))
ans = 0
a_sum = sum(a)
a_sum -= a[0]
for i in range(n - 1):
ans += a[i] * a_sum
a_sum -= a[i + 1]
ans %= 1000000007
print(ans)
|
p02572 | s037350660 | Accepted | N,*A = map(int, open(0).read().split())
Asq=[a**2 for a in A]
S = (sum(A)**2-sum(Asq))//2
print(S%(10**9+7)) |
p02572 | s986647097 | Accepted | a=input()
b=input().split()
N=int(a)
c=[]
ans=0
for i in range(N):
c.append(int(b[i]))
s=sum(c)
for i in range(N):
s=s-c[i]
ans+=c[i]*s
print(ans%1000000007) |
p02572 | s791628091 | Accepted | n=int(input())
a=list(map(int,input().split()))
ans=0
cum=[0]
for i in range(n):
cum.append((cum[i]+a[i])%(10**9+7))
for i in range(n):
# print(a[i],cum[-1]-cum[i+1])
ans+=a[i]*(cum[-1]-cum[i+1])%(10**9+7)
ans%=(10**9+7)
print(ans) |
p02572 | s660394082 | Accepted | N = int(input())
input = [int(s) for s in input().split()]
ans = 0
temp=sum(input)
for i in range(N-1):
temp=temp-input[i]
ans = (ans + (input[i]*((temp)%(10**9+7)))%(10**9+7))%(10**9+7)
print(ans) |
p02572 | s665470236 | Accepted | import sys
MOD = 10 ** 9 + 7
def main():
input = sys.stdin.buffer.readline
n = int(input())
a = list(map(int, input().split()))
ans = sum(a) ** 2
for e in a:
ans -= e ** 2
ans //= 2
ans %= MOD
print(ans)
if __name__ == "__main__":
main()
|
p02572 | s472080228 | Accepted | MODINT = 1000000007
n = int(input())
A = list(map(int,input().split()))
prodsum = [0]*n
prodsum[0] = A[0]
for i in range(1,n):
prodsum[i] = prodsum[i-1]+A[i]
# print(prodsum)
ans = 0
for i in range(n-1):
ans += A[i]*(prodsum[-1]-prodsum[i])
print(ans%MODINT)
|
p02572 | s572136892 | Accepted | n=int(input())
a=list(map(int,input().split()))
x=0
for i in range(n):
x+=a[i]
x=x**2
y=0
for j in range(n):
y+=a[j]**2
z=(x-y)//2
print(z%(10**9+7)) |
p02572 | s244162179 | Accepted | #!/usr/bin/env python3
def main():
_ = int(input())
A = [int(x) for x in input().split()]
mod = 10 ** 9 + 7
sum_A = sum(A) % mod
ans = 0
for a in A:
sum_A -= a
if sum_A < 0:
sum_A += mod
ans += a * sum_A
ans %= mod
print(ans % mod)
if __name__ == '__main__':
main()
|
p02572 | s932265206 | Accepted | from itertools import accumulate
N = int(input())
A = list(map(int,input().split()))
mod = 10 ** 9 + 7
ruiseki = list(accumulate(A))
ans = 0
for i in range(N-1):
ans += A[i] * (ruiseki[-1] - ruiseki[i])
ans %= mod
print(ans) |
p02572 | s675194076 | Accepted | N = int(input())
A = list(map(int,input().split()))
s =0
M = 10**9 +7
As = sum(A)
for i in range(N-1):
As = As - A[i]
s += (A[i] * As)%M
print(s%M) |
p02572 | s863894346 | Accepted | n=int(input())
x = list(map(int, input().split()))
total=0
t=sum(x)
for i in range(n):
t=t-x[i]
total=total+x[i]*(t)
print(total %1000000007)
|
p02572 | s826373611 | Accepted | N = int(input())
A = list(map(int, input().split()))
mem = []
h = 0
for i in range(N-1, -1, -1):
h += A[i]
mem.append(h)
tmp = 0
for i in range(N-1):
tmp += A[i]*mem[-(i+1+1)]
print(tmp % (10**9+7))
|
p02572 | s343068297 | Accepted | n=int(input())
a=list(map(int,input().split()))
ans=0
num=0
for i in range(n-1):
num+=a[i]
ans+=a[i+1]*num
print(ans%1000000007) |
p02572 | s907860533 | Accepted | N=int(input())
A=list(map(int,input().split()))
modular=10**9+7
sum=0
AllSum=0
for i in range(N):
AllSum+=A[i]
AllSum=AllSum%modular
RuisekiWa=[]
NextSum=AllSum
for i in range(N):
RuisekiWa.append((NextSum-A[i])%modular)
NextSum=RuisekiWa[i]
#print(RuisekiWa)
for i in range(N):
sum+=(A[i]*RuisekiWa[i])%modular
sum=(sum%modular)
print(sum%modular)
|
p02572 | s939860103 | Accepted | from itertools import accumulate
def solve():
N = int(input())
A = list(map(int,input().split()))
MOD = 10**9+7
accm = list(accumulate(A))
ans = 0
for i in range(N-1,0,-1):
ans += A[i] * accm[i-1] % MOD
ans %= MOD
print(ans%MOD)
if __name__ == '__main__':
solve()
|
p02572 | s515302721 | Accepted | from sys import stdin, stdout
import heapq
import cProfile
from collections import Counter, defaultdict, deque
from functools import reduce
import math
from itertools import accumulate
def get_int():return int(stdin.readline().strip())
def get_tuple():return map(int, stdin.readline().split())
def get_list():return list(map(int, stdin.readline().split()))
n = get_int()
ls = get_list()
mod = 10**9+7
pref_sum = list(accumulate(ls))
ans = 0
for i in range(1,n):
ans = (ans+ls[i]*(pref_sum[i]-ls[i]))%mod
print(ans) |
p02572 | s949511595 | Accepted | n = int(input())
aaa = list(map(int, input().split()))
ans = 0
mod = 10 ** 9 + 7
sum_a = [0] * len(aaa)
sum_a[0] = aaa[0]
for i in range(n - 1):
sum_a[i + 1] = sum_a[i] + aaa[i + 1]
for i in range(n):
ans += aaa[i] * (sum_a[n -1] - sum_a[i])
print(ans%mod)
|
p02572 | s925070629 | Accepted | n=int(input())
vec=list(map(int,input().split()))
mod=10**9+7
wa=[i for i in vec]
for i in range(n-1):
wa[i+1]+=wa[i]
ans=0
for i in range(n):
ans += vec[i]*((wa[n-1]-wa[i])%mod)%mod
ans %= mod
print(ans) |
p02572 | s630779683 | Accepted | n = int(input())
a = list(map(int,input().split()))
p = 10 ** 9 + 7
suma = 0
dsum = 0
for i in a:
suma = (suma + i) % p
dsum = (dsum + i ** 2) % p
sa2 = (suma ** 2) % p
ans2 = (sa2 - dsum) % p
if ans2 % 2 == 0:
ans = ans2 // 2
else:
ans = (ans2+p) // 2
print(ans) |
p02572 | s385720651 | Accepted | #template
def inputlist(): return [int(j) for j in input().split()]
#template
mod = 10**9 + 7
N = int(input())
A = inputlist()
s = sum(A)
ans = 0
for i in range(N):
s -= A[i]
ans += A[i]*s
ans %= mod
print(ans) |
p02572 | s104510150 | Accepted | N=int(input())
A = list(map(int,input().split()))
mod=1000000007
ans=0
sumA=sum(A)
for i in range(N-1):
sumA-=A[i]
a=A[i]*sumA
a%=mod
ans+=a
ans%=mod
print(ans) |
p02572 | s315313505 | Accepted | N = int(input())
A = list(map(int, input().split()))
mod = 10**9 + 7
s = sum(A) % mod
s += mod
ss = 0
for i in range(N):
ss += A[i]**2 % mod
ss = ss % mod
if (s**2 - ss) % 2 == 1:
ss -= mod
print((((s**2) - ss) // 2) % mod) |
p02572 | s306388920 | Accepted | n = int(input())
a = list(map(int, input().split()))
a.sort()
n_sum = a[0]
sum = 0
for i in range(1,n):
sum += a[i] * n_sum
n_sum += a[i]
print(sum % (10**9 + 7))
|
p02572 | s735696458 | Accepted | n = int(input())
A = list(map(int, input().split()))
Sum = sum(A)
square_sum = sum(map(lambda x:x*x, A))
print((Sum*Sum - square_sum)//2%(10**9+7)) |
p02572 | s131169209 | Accepted | # coding: utf-8
N= int(input())
A=list(map(int,input().split()))
cA = [A[-1]]
MOD = 10**9+7
for i in range(N-1):
cA.append(cA[-1]+A[-2-i])
ans=0
cA.reverse()
for i in range(N-1):
ans+=A[i]*cA[i+1]
ans=ans%MOD
print(ans) |
p02572 | s437755983 | Accepted | def square(list):
return [i ** 2 for i in list]
m = 1000000007
n = int(input())
A = list(map(int, input().split()))
sq = square(A)
s1 = sum(A)
s2 = sum(sq)
result = (s1**2-s2)//2
print(result%m) |
p02572 | s550792730 | Accepted | import sys
input = sys.stdin.readline
N = int(input())
A = list(map(int, input().split()))
mod = int(1e9+7)
sum = 0
row = 0
for ii in range(N-1):
i = N-2-ii
row += A[i+1]
row %= mod
sum += A[i] * row
sum %= mod
print(sum) |
p02572 | s080506840 | Accepted | n = int(input())
a = list(map(int,input().split()))
sum = 0
ans = 0
dp=[]
for i in reversed(range(1,n)):
sum += int(a[i])
dp.append(sum % (10**9+7))
for i in range(n-1):
ans += a[i] * dp[n-2-i]
ans %= (10**9+7)
print(ans)
|
p02572 | s312027719 | Accepted | N=int(input())
A=list(map(int,input().split()))
mod=10**9+7
buf=0
s=0
for k in range(N-1):
buf=(buf+A[N-1-k])%mod
s=(s+A[N-2-k]*buf)%mod
print(s)
|
p02572 | s651117335 | Accepted | from itertools import accumulate
N = int(input())
A = list(map(int, input().split()))
MOD = 1_000_000_007
acc = list(accumulate(A, initial=0))
ans = 0
for i in range(N):
ans += A[i] * (acc[N] - acc[i + 1])
ans %= MOD
print(ans)
|
p02572 | s750791544 | Accepted | N = int(input())
A = list(map(int, input().split()))
S = sum(A)%(10**9+7)
ans = 0
for i in range(N-1):
S -= A[N-i-1]
ans += S*A[N-i-1]%(10**9+7)
print(ans%(10**9+7)) |
p02572 | s637569094 | Accepted | N=int(input())
A=list(map(int,input().split()))
s=sum(A)
ans=0
for i in A[:N-1]:
s-=i
ans+=s*i
ans%=10**9+7
print(ans)
|
p02572 | s770532616 | Accepted | def resolve():
N = int(input())
A = list(map(int, input().split()))
S = sum(A)
res = 0
v = 10**9+7
for i in range(N-1):
S -= A[i]
res += A[i] * S
print(res%v)
resolve() |
p02572 | s679151396 | Accepted | n = int(input())
a = [int(x) for x in input().split()]
pref = [0]*(n+1)
for i in range(n + 1):
pref[i] = pref[i - 1] + a[i - 1]
answer = 0
for i in range(n - 1):
answer += (pref[n] - pref[i + 1]) * a[i]
answer %= (10 ** 9 + 7)
print(answer) |
p02572 | s917842957 | Accepted | def main():
N = int(input())
A = list(map(int, input().split()))
MOD = 10 ** 9 + 7
b = A[0]
ans = 0
for i in range(1, N):
ans = (ans + b * A[i]) % MOD
b = (b + A[i]) % MOD
print(ans)
if __name__ == '__main__':
main() |
p02572 | s612303756 | Accepted | N=int(input())
A=list(map(int,input().split()))
sum_mod=[0]
for i in range(N):
sum_mod+=[(sum_mod[i]+A[i])%(10**9+7)]
ans=0
for i in range(N):
ans=(ans+sum_mod[i]*A[i])%(10**9+7)
print(ans) |
p02572 | s045763624 | Accepted | N = int(input())
Alist = list(map(int,input().split()))
M = 10**9+7
Asum = sum(Alist)
Answer = 0
for i in range(len(Alist)):
Asum -= Alist[i]
Answer += (Alist[i]%M)*(Asum%M)
Answer = Answer%M
print(Answer) |
p02572 | s950272222 | Accepted | N = int(input())
A = list(map(int, input().split()))
x, y = 0, 0
mod = 10**9+7
for a in A:
x = (x + a) % mod
y = (y + a * a) % mod
print((x * x % mod - y) * pow(2, mod - 2, mod) % mod)
|
p02572 | s539541731 | Accepted | _ = input()
A = list(map(int, input().split()))
mod = 10**9 + 7
s = 0
a = 0
for _a in A:
s += _a * a
a = (a + _a) % mod
print(s % mod)
|
p02572 | s453492421 | Accepted | n = int(input())
A = list(map(int, input().split()))
S = sum(A)**2 - sum(map(lambda x:x**2, A))
print(S//2 % 1000000007)
|
p02572 | s942950907 | Accepted | N = int(input())
A = list(map(int, input().split()))
s = sum(A)
sumpro = 0
for a in A[:-1]:
s -= a
sumpro += a * s
print(sumpro % (10 ** 9 + 7))
|
p02572 | s889175264 | Accepted | N = int(input())
A = [int(a) for a in input().split()]
p = 10 ** 9 + 7
S = [A[0]] * N
for i in range(1, N):
S[i] = S[i - 1] + A[i]
sum = 0
for i in range(0, N - 1):
sum += (A[i] * (S[N - 1] - S[i])) % p
print(sum % p) |
p02572 | s478101724 | Accepted | def main():
N = int(input())
A = list(map(int, input().split()))
mod = 7 + 10**9
s = sum(A)
s %= mod
r = 0
for i in range(N):
s -= A[i]
r += s * A[i]
r %= mod
return r
print(main())
|
p02572 | s573070446 | Accepted | n = int(input())
a = list(map(int,input().split()))
par = [0] * n
par[0] = a[0]
mod = 10**9 + 7
for i in range(1,n):
par[i] = par[i-1] + a[i]
par[i] = par[i] % mod
ans = 0
#print(par)
for i in range(n-1):
ans += a[i] * (par[-1] - par[i])
ans = ans % mod
print(ans%mod) |
p02572 | s948471569 | Accepted | n = int(input())
a = list(map(int, input().split()))
mod = 10 ** 9 + 7
res = sum([a[i] ** 2 for i in range(n)])
s = sum(a)
ans = (s ** 2 - res) // 2
ans %= mod
print(ans) |
p02572 | s166057702 | Accepted | N=int(input())
A=list(map(int,input().split()))
Asum=sum(A)
ans=0
for i in range(len(A)-1):
Asum-=A[i]
ans+=A[i]*Asum
print(ans%1000000007) |
p02572 | s075432149 | Accepted | n = int(input())
an = list(map(int, input().split()))
sum_an = sum(an)
total = 0
for ai in an:
total = total + ai * (sum_an - ai)
sum_an = sum_an - ai
print(total % ((pow(10, 9) + 7))) |
p02572 | s452329977 | Accepted |
N = int(input())
n_list = list(map(int,input().split()))
result = 0
s = sum(n_list)
m = 10**9+7
for num in n_list:
s -= num
result += num * s % m
result %= m
print(result)
|
p02572 | s909850819 | Accepted | n = int(input())
a = list(map(int, input().split()))
def mod(x):
return x%(10**9+7)
sum_num = 0
ans = 0
for i in range(len(a)-1):
idx = len(a)-i-1
sum_num += a[idx]
sum_num = mod(sum_num)
ans += sum_num*a[idx-1]
ans = mod(ans)
print(ans)
|
p02572 | s906123581 | Accepted | n = int(input())
a = [int(i) for i in input().split()]
sum1 = 0
sum2 = 0
for _ in a:
sum1 += _
sum2 += (_*_)
sum1 = (sum1 * sum1)
print(((sum1 - sum2)//2)%1000000007)
|
p02572 | s404535527 | Accepted | N = int(input())
A = list(map(int, input().split()))
r = [A[0]]
m = 10**9 + 7
ans = 0
for i in range(1, N):
r.append(A[i] + r[i - 1])
for i in range(N - 1):
ans += A[i] * (r[N - 1] - r[i])
ans = ans % m
print(ans) |
p02572 | s146024294 | Accepted | import numpy
n=int(input())
l=list(map(int, input().split()))
res=0
mod=10**9+7
l.append(0)
l.reverse()
cum=numpy.cumsum(l)%mod
for i in range(n):
res+=((l[n-i]%mod)*cum[n-i-1])%mod
print(res%mod) |
p02572 | s384488749 | Accepted | N = int(input())
A = list(map(int, input().split()))
S = 0
for i in range(N):
S += A[i]
c = S
d = 0
for j in range(N):
c -= A[j]
c = c%(10**9+7)
d += A[j]*c
d = d%(10**9+7)
print(d) |
p02572 | s563439670 | Accepted | n = int(input())
a = list(map(int, input().split()))
s = 0
c = sum(a)
for i in range(n-1):
c -= a[i]
s += a[i] * c
print(s % (10**9+7)) |
p02572 | s158324807 | Accepted | N = int( input().strip() ) ;
arr = list ( map ( int , input().strip().split(" ") ) ) ;
mod = pow ( 10, 9 ) + 7 ;
arr2 = [ 0 for x in range ( N ) ] ;
for x in range ( N -1 , 0 , -1 ) :
if x == N -1 :
arr2[x] = arr[x] ;
else :
arr2[x] = ( arr[x] + arr2[x+1] ) % mod ;
t = 0 ;
for x in range ( N -1 ) :
t += ( arr[x] * arr2[x+1] ) % mod ;
t %= mod ;
print ( t ) ;
|
p02572 | s812523819 | Accepted | #!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# FileName: C_fix_2
# CreatedDate: 2020-08-29 22:01:34 +0900
# LastModified: 2020-08-29 22:07:06 +0900
#
import os
import sys
import numpy as np
# import pandas as pd
def main():
n = int(input())
A = list(map(int, input().split()))
amari = 1000000007
ans = ((sum(A))*(sum(A)) - sum(a**2 for a in A))
print(ans//2%amari)
if __name__ == "__main__":
main()
|
p02572 | s905933854 | Accepted | N = int(input())
A = input().split()
B = [0]*N
for i in range(N):
A[i] = int(A[i])
B[i] = A[i]*A[i]
print( ( ( (sum(A)*sum(A)) - sum(B) ) // 2 ) % ( 10**9 + 7 ) )
|
p02572 | s982389486 | Accepted | import math
N = int(input())
An = [int(i) for i in input().split()]
mod = int(math.pow(10, 9) + 7)
sum_an = sum(An)
sum_result = 0
for i in range(N - 1):
Ai = An[i]
sum_an -= Ai
sum_result += (Ai * sum_an) % mod
print(sum_result % mod)
|
p02572 | s560745249 | Accepted | N = int(input())
A = list(map(int, input().split()))
Asum = sum(A)
A2sum = 0
for i in range(N):
A2sum += A[i]**2
print(((Asum**2-A2sum)//2)%(10**9+7)) |
p02572 | s736583941 | Accepted | n=int(input())
L=list(map(int,input().split()))
cnt=0
for i in range(n):
cnt+=L[i]**2
ans=(sum(L)**2-cnt)//2
mod=pow(10,9)+7
print(ans%mod) |
p02572 | s111756257 | Accepted | from itertools import accumulate
MOD = 10**9 + 7
N = int(input())
A = list(map(int, input().split()))
A_cumsum = list(accumulate(A))
ans = 0
for i in range(N-1):
ans += A[i] * (A_cumsum[-1] - A_cumsum[i]) % MOD
print(ans % MOD) |
p02572 | s635732214 | Accepted | #!/usr/bin/env python
# coding: utf-8
def ri():
return int(input())
def rl():
return list(input().split())
def rli():
return list(map(int, input().split()))
def main():
n = ri()
la = rli()
su = sum(la)
ans = 0
mod = 10**9+7
for a in la:
su -= a
ans += su*a
ans %= mod
print(ans)
if __name__ == '__main__':
main()
|
p02572 | s317763378 | Accepted | N=int(input())
A=list(map(int,input().split()))
B=[]
for i in range(N):
B.append(A[i]**2)
ans=(sum(A)**2-sum(B))//2
print(ans%(10**9+7)) |
p02572 | s787704744 | Accepted | N = int(input())
A = list(map(int, input().split()))
mod = 10**9 + 7
s = sum(A[1:])
ans = 0
for i in range(N-1):
ans += (A[i] * s) % mod
s -= A[i+1]
print(ans%mod) |
p02572 | s394946231 | Accepted | mod = 10**9+7
n = int(input())
num = list(map(int,input().split()))
ans = 0
s = sum(num)
for i in num:
s -= i
ans += i*s
print(ans%mod) |
p02572 | s574428716 | Accepted | def main():
N = int(input())
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
A_cum_sum = [A[-1]]
for a in A[::-1][1:]:
A_cum_sum.append(a + A_cum_sum[-1])
A_cum_sum = A_cum_sum[::-1]
ans = 0
for i in range(N-1):
sum_mod = A_cum_sum[i+1] % mod
mul_mod = (A[i] * sum_mod) % mod
ans = (ans + mul_mod) % mod
print(ans)
if __name__ == '__main__':
main()
|
p02572 | s078795912 | Accepted | n = int(input())
a = list(map(int, input().split()))
s = sum(a)
s2 = sum(map(lambda x:x*x, a))
print((s**2-s2)//2 % (10**9+7)) |
p02572 | s113874020 | Accepted | N = int(input())
A = list(map(int, input().split()))
cum_A = [0]
mod = (10 ** 9) + 7
for i in range(N):
cum_A.append((cum_A[i] + A[i]))
ans = 0
for i, a in enumerate(A):
#print(f"{a}*{cum_A[N] - cum_A[i + 1]}")
ans += a * ((cum_A[N] - cum_A[i + 1]) % mod)
ans %= mod
#print(ans)
print(ans)
|
p02572 | s895591360 | Accepted | N = int(input())
A = list(map(int,input().split()))
mod = 1000000007
sum_A = 0
for i in range(N):
A[i] = A[i] % mod
sum_A += A[i]
ans = 0
for i in range(N-1):
sum_A -= A[i]
ans = (ans + (A[i] * sum_A) % mod) % mod
print(ans)
|
p02572 | s541265011 | Accepted | N=int(input())
MOD=10**9+7
A=[int(x) for x in input().split()]
sumA=sum(A)
ans=0
for i in range(N):
now=A[i]
sumA-=now
ans+=now*sumA
ans%=MOD
print(ans) |
p02572 | s572921144 | Accepted | from sys import stdin
nii=lambda:map(int,stdin.readline().split())
lnii=lambda:list(map(int,stdin.readline().split()))
n=int(input())
a=lnii()
total=sum(a)
mod=10**9+7
ans=0
for i in range(n-1):
total-=a[i]
ans+=a[i]*total
ans%=mod
print(ans) |
p02572 | s565423587 | Accepted | n,a,m,s,r = int(input()),list(map(int,input().split())),(10**9)+7,0,0
for i in range(n): s = (s+a[i])%m
for i in range(n):
s = (s-a[i])%m
r = (r+(a[i]*s))%m
print(r%m)
|
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