input stringlengths 20 127k | target stringlengths 20 119k | problem_id stringlengths 6 6 |
|---|---|---|
ans = 0
mod = 1e9+7
N = int(eval(input()))
A = [int(num)%mod for num in input().split()]
for i in range(N-1):
for j in range(i+1, N):
ans += A[i]*A[j]
ans = int(ans%mod)
print(ans) | n = int(eval(input()))
a = list(map(int, input().split()))
b = sum(a)
ans = 0
for i in range(n-1):
ans += a[i] *(b-a[i])
b = b - a[i]
print((ans % (10**9 + 7))) | p02572 |
N=int(eval(input()))
A=list(map(int,input().split()))
mod=10**9+7
ans=0
for i in range(N-1):
for j in range(i+1,N):
ans+=(A[i]*A[j])%mod
print((ans%mod))
|
N=int(eval(input()))
A=list(map(int,input().split()))
mod=10**9+7
sumA=sum(A)
ans=0
for i in range(N):
ans+=(A[i]*(sumA-A[i]))
ans=ans//2
print((ans%mod))
| p02572 |
N=int(eval(input()))
List = list(map(int, input().split()))
res=0
for i in range(N-1):
a = List[i] % 1000000007
for j in range(i+1,N):
b = List[j] % 1000000007
res += a*b
print((res%1000000007)) | N=int(eval(input()))
List = list(map(int, input().split()))
midList = [0]*(N-1)
mid = 0
for i in range(N-2,-1,-1):
mid += List[i+1]
midList[i] = mid
res=0
for i in range(N-1):
a = List[i] % 1000000007
b = midList[i] % 1000000007
res += a*b
print((res%1000000007)) | p02572 |
import sys
sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI(): return list(map(int,sys.stdin.readline().rstrip().split())) #空白あり
def LI2(): return list(map(int,sys.stdin.readline().rstrip())) #空白なし
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split()) #空白あり
def LS2(): return list(sys.stdin.readline().rstrip()) #空白なし
N = I()
A = LI()
mod = 10**9+7
ans = sum(A)**2
ans %= mod
a = sum(A[i]**2 for i in range(N))
a %= mod
ans -= a
ans *= pow(2,mod-2,mod)
ans %= mod
print(ans)
| import sys
def I(): return int(sys.stdin.readline().rstrip())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split())) #空白あり
N = I()
A = LI()
mod = 10**9+7
ans = sum(A)**2-sum(A[i]**2 for i in range(N))
ans %= mod
ans *= pow(2,mod-2,mod)
ans %= mod
print(ans)
| p02572 |
import sys
def I(): return int(sys.stdin.readline().rstrip())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split())) #空白あり
N = I()
A = LI()
mod = 10**9+7
ans = sum(A)**2-sum(A[i]**2 for i in range(N))
ans %= mod
ans *= pow(2,mod-2,mod)
ans %= mod
print(ans)
| import sys
sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI(): return list(map(int,sys.stdin.readline().rstrip().split())) #空白あり
def LI2(): return list(map(int,sys.stdin.readline().rstrip())) #空白なし
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split()) #空白あり
def LS2(): return list(sys.stdin.readline().rstrip()) #空白なし
N = I()
A = LI()
s = sum(A)
mod = 10**9+7
s %= mod
a = s**2-sum(A[i]**2 for i in range(N))
a %= mod
a *= pow(2,mod-2,mod)
a %= mod
print(a)
| p02572 |
from itertools import combinations
n = int(eval(input()))
A = list(map(int, input().split()))
ans = 0
mod = 10**9 + 7
p = list(combinations(A,2))
for i in range(len(p)):
ans += p[i][0] * p[i][1]
print((ans%mod))
| n = int(eval(input()))
A = list(map(int, input().split()))
ans = 0
mod = 10**9 + 7
# p = list(combinations(A,2))
for i in range(len(A)-1):
for j in range(i+1, len(A)):
# ans += p[i][0] * p[i][1]
#print(A[i], A[j])
ans += A[i] * A[j]
print((ans%mod))
| p02572 |
n=int(eval(input()))
lst=list(map(int,input().split()))
# print(sum(lst))
tem=0
for i in range(n-1):
for j in range(i+1,n):
tem+=(lst[i] % (10**9+7) )*(lst[j] % (10**9+7) )
# print(tem)
print((tem % (10**9 +7))) | n=int(eval(input()))
lst=list(map(int,input().split()))
aa=sum(lst) % (10**9+7)
# print(sum(lst) % (10**9+7) )
new_lst=[]
temp_1=aa
for i in range(n-1):
temp_1-=lst[i]
new_lst.append(temp_1)
# print(new_lst)
tem=0
for i in range(n-1):
tem+=(lst[i] )*new_lst[i]
# print(tem)
print((tem % (10**9 +7)))
| p02572 |
mod=1000000007
n=int(eval(input()))
#n,k=map(int,input().split())
a=[int(i) for i in input().split()]
ans=chk=0
for i in range(n-1):
for j in range(i+1,n):
ans+=(a[i]*a[j])%mod
ans%=mod
print(ans) | mod=1000000007
n=int(eval(input()))
#n,k=map(int,input().split())
a=[int(i) for i in input().split()]
t=[0]*(n+1)
for i in range(n):
t[i]=t[i-1]+a[i]
ans=chk=0
#print(t)
for i in range(n-1):
# print(-(i+1))
x=-1*(i+1)
# print(x)
# print(a[x],t[x-2])
ans+=a[x]*t[x-2]
ans%=mod
print(ans) | p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
num=0
for i in range(n):
for j in range(n-1,i,-1):
num=num+a[i]*a[j]
else:
print((num % 1000000007)) | n=int(eval(input()))
l = 1000000007
a=list(map(int,input().split()))
s = sum(a)
num = 0
for i in range(n):
s = s- a[i]
num =num+a[i]*s
else:
print((num%l))
| p02572 |
n = int(eval(input()))
A = list(map(int, input().split()))
mod = 10**9+7
cs = [0]
for a in A:
cs.append(cs[-1]+a)
cs = cs[1:]
ans = 0
for i in range(n):
ans += A[i] * (cs[-1]-cs[i])
ans %= mod
print(ans) | n = int(eval(input()))
A = list(map(int, input().split()))
mod = 10**9+7
x = (((sum(A))**2) // 2)
x -= (sum([a**2 for a in A]) // 2)
x %= mod
print(x) | p02572 |
import itertools
n = int(eval(input()))
num_list = list(map(int, input().split()))
mod = (10**9)+7
comb = list(itertools.combinations(num_list, 2))
sum = 0
for tuple in comb:
tmp = (tuple[0]*tuple[1])%mod
sum += tmp
ans = sum%mod
print(ans) | import itertools
n = int(eval(input()))
num_list = list(map(int, input().split()))
lists = [i for i in num_list if i != 0]
mod = (10**9)+7
mod_list = []
sum = 0
for i in range(len(num_list)-1):
for j in range(i+1, len(num_list), 1):
if num_list[i] == 0 or num_list[j] == 0:
continue
else:
tmp = (num_list[i]*num_list[j])%mod
sum += tmp
ans = sum%mod
print(ans) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
s = 0
m = 1000000007
for i in range(n):
if i == n-1:
pass
else:
for j in range(i+1, n):
s += a[i] * a[j]
s = s % m
print(s)
| n = int(eval(input()))
a = list(map(int, input().split()))
m = 1000000007
s = sum(a)
ans = 0
for i in range(n):
aa = a[i]
ans += aa * (s - aa)
ans = ans//2
ans = ans % m
print(ans)
| p02572 |
n = int(eval(input()))
li_a = list(map(int, input().split()))
answer = 0
mo = (10 ** 9) + 7
for idx, a in enumerate(li_a):
answer += (a * sum(li_a[idx + 1:]))
print((answer % mo)) | n = int(eval(input()))
li_a = list(map(int, input().split()))
answer = 0
su = sum(li_a)
mo = (10 ** 9) + 7
for idx, a in enumerate(li_a):
su = su - a
answer += (a * su)
print((answer % mo)) | p02572 |
n = int(eval(input()))
aaa = list(map(int, input().split()))
mod = 1000000007
ans = 0
for i in range(n - 1):
for j in range(i + 1, n):
ans += aaa[i] * aaa[j] % mod
ans %= mod
print(ans) | n = int(eval(input()))
aaa = list(map(int, input().split()))
mod = 1000000007
c_sum = [0] * n
c_sum[n - 1] = aaa[n - 1]
ans = 0
for i in range(n - 2, 0, -1):
c_sum[i] = (c_sum[i + 1] + aaa[i]) % mod
for i in range(n - 1):
ans += aaa[i] * c_sum[i + 1] % mod
ans %= mod
print(ans) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
s = sum(a)
for i in range(n):
s-=a[i]
ans += a[i]*s
print((ans%(10 ** 9 + 7))) | MOD = 10 ** 9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
s = sum(a) % MOD
ans = 0
for i in a:
s-=i
s%=MOD
ans+=s*i
ans%=MOD
print(ans) | p02572 |
n = int(eval(input()))
a = list(map(int,input().split()))
b = 0
for m in range(n-1):
d = sum(a[m+1:n])
b = b + a[m]*d
if b >= 10**9+7:
b = b % (10**9+7)
print(b) | n = int(eval(input()))
a = list(map(int,input().split()))
b = 0
d = sum(a)
for m in range(n-1):
d = d -a[m]
b = b + a[m]*d
if b >= 10**9+7:
b = b % (10**9+7)
print(b) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split(" ")))
res = 0
for j in range(n):
sum_i = 0
for i in range(j):
sum_i += a[i]
res = res + a[j]*sum_i
print((res % ((10 **9)+7))) | n = int(eval(input()))
a = list(map(int, input().split(" ")))
res = 0
ruiseki = 0
for j in range(n):
if j == 0:
continue
ruiseki += a[j-1]
res = res + a[j]*ruiseki
print((res % ((10 **9)+7))) | p02572 |
def resolve():
import sys
input = sys.stdin.readline
n = input().rstrip()
a_list = []
ans = 0
for a in input().rstrip().split(" "):
a = int(a)
for past_a in a_list:
ans += a * past_a
a_list.append(a)
x = 1000000007
ans = ans % x
print(ans)
if __name__ == "__main__":
resolve() | def resolve():
import sys
input = sys.stdin.readline
n = input().rstrip()
past_a = 0
ans = 0
for a in input().rstrip().split(" "):
a = int(a)
ans += a * past_a
past_a += a
x = 1000000007
ans = ans % x
print(ans)
if __name__ == "__main__":
resolve()
| p02572 |
N = int(eval(input()))
As = list(map(int, input().split()))
m = 10**9 + 7
result = 0
for i in range(N-1):
p = As[i]
cs_mod = sum(As[i+1:]) % m
result += ((cs_mod * p) % m)
print((result % m)) | N = int(eval(input()))
As = list(map(int, input().split()))
m = 10**9 + 7
result = 0
As_sum = sum(As)
for i in range(N-1):
As_sum = As_sum - As[i]
result += (As[i] * As_sum) % m
print((result % m)) | p02572 |
import itertools
import operator
N = int(eval(input()))
A = list(map(int, input().split()))
AA = []
for i in range(len(list(itertools.combinations(A, 2)))):
n = list(itertools.combinations(A, 2))
if n[i][0]*n[i][1] >= (10**9+7):
num = n[i][0]*n[i][1]%(10**9 +7)
AA.append(n[i][0]*n[i][1])
if sum(AA) >= (10**9 +7):
print((sum(AA)%(10**9 +7)))
else:
print((sum(AA)))
| N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10**9 + 7
S = sum(A)%mod
ans = 0
for x in A:
S -= x
S %= mod
ans += S * x
ans %= mod
ans %= mod
print(ans) | p02572 |
MOD = 1000000007
n = int(eval(input()))
str_ary = input().split()
ary = [int(c) for c in str_ary]
# ary = []
# queue = [0 for i in range(n)]
# for i int range(n):
# num = int(str_ary[i])
# ary.append(num)
# for j int range(i):
# pre_queue = []
# queue.append(pre_queue)
sum = 0
for diff in range(n - 1):
for i in range(n - diff - 1):
# print(i, i + diff + 1)
sum += ary[i] * ary[i + diff + 1] % MOD
# for i in range(n):
# sum = 0
# for j in range(n - i - 1):
# # print(i, j + i + 1)
# sum += ary[j + i + 1]
# result += ary[i] * sum
print((sum % MOD)) | MOD = 1000000007
n = int(eval(input()))
str_ary = input().split()
ary = [int(c) for c in str_ary]
# ary = []
# queue = [0 for i in range(n)]
# for i int range(n):
# num = int(str_ary[i])
# ary.append(num)
# for j int range(i):
# pre_queue = []
# queue.append(pre_queue)
result = 0
sum = sum(ary[i] for i in range(n))
# for diff in range(1, n):
# for i in range(n - diff):
# # print(diff, i, i + diff)
# sum += ary[i] * ary[i + diff] % MOD
for i in range(n):
sum -= ary[i]
result += ary[i] * sum
print((result % MOD)) | p02572 |
#!/usr/bin/env python
# -*- coding: utf-8 -*-
def main():
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]
print((ans % (10**9 + 7)))
if __name__ == "__main__":
main()
| #!/usr/bin/env python
# -*- coding: utf-8 -*-
def main():
N = int(eval(input()))
A = list(map(int, input().split()))
s = sum(A)
ans = 0
mod = 10**9 + 7
for i in A:
ans = (ans + i * (s - i))
print(((ans // 2) % mod))
if __name__ == "__main__":
main()
| p02572 |
n=int(eval(input()))
a=list(map(int,input().split()))
from itertools import combinations
MOD = 10**9+7
result = 0
for seq in combinations(list(range(0, n)), 2):
result += a[seq[0]] * a[seq[1]] % MOD
print((result%MOD))
| n=int(eval(input()))
a=list(map(int,input().split()))
s=[0]*(n+1)
for i in range(n):
s[i+1] = s[i] + a[i]
MOD = 10**9+7
result = 0
for i in range(n):
result += a[i]*(s[n] - s[i+1])%MOD
print((result%MOD))
| p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(n - 1):
b = a[0]
a.pop(0)
ans += b * sum(a)
print((ans % (10 ** 9 + 7)))
| n = int(eval(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 |
n=int(eval(input()))
mod=10**9+7
a=list(map(int,input().split()))
total=0
for i in range(n-1):
total+=a[i]%mod * (sum(a[i+1:]))%mod
total%=mod
print(total)
| n=int(eval(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 |
n = int(eval(input()))
a = list(map(int, input().split()))
result = 0
for i in range(n):
for j in range(i + 1, n):
result += a[i] * a[j]
result = result % (10**9 + 7)
print(result)
| n = int(eval(input()))
a = list(map(int, input().split()))
sum_a = 0
result = 0
for i in range(n):
sum_a += a[i]
for j in range(n):
sum_a -= a[j]
result += sum_a * a[j]
print((result % (10**9 + 7))) | p02572 |
def solve():
N = int(eval(input()))
AA = list(map(int,input().split()))
ans = 0
for a in AA:
ans += a
ans = ans % (10**9+7)
ans = ans**2
ans = ans % (10**9+7)
for a in AA:
aa = (a**2) % (10**9+7)
ans -= a**2
while ans<0:
ans += 10**9+7
ans = ans % (10**9+7)
print((int(ans/2)))
solve() | def solve():
N = int(eval(input()))
AA = list(map(int,input().split()))
ans = 0
for a in AA:
ans += a
ans = ans**2
for a in AA:
ans -= a**2
ans = ans//2
print((ans%(10**9+7)))
solve() | p02572 |
def main():
n=int(eval(input()))
a=sorted(map(int,input().split()), reverse=True)
ans=0
mod=10**9+7
for i in range(n-1):
if a[i] == 0:
break
for j in range(i+1,n):
if a[j] == 0:
break
ans += a[i]*a[j]%mod
print((ans%mod))
if __name__ == '__main__':
main() | from itertools import accumulate
def main():
mod=10**9+7
n=int(eval(input()))
a=list(map(int,input().split()))
aa=[0]+list(accumulate(a))
ans=0
for i in range(n-1):
ans += a[i]*(aa[-1]-aa[i+1])%mod
print((ans%mod))
if __name__ == '__main__':
main() | p02572 |
from itertools import accumulate
def main():
mod=10**9+7
n=int(eval(input()))
a=list(map(int,input().split()))
aa=[0]+list(accumulate(a))
ans=0
for i in range(n-1):
ans += a[i]*(aa[-1]-aa[i+1])%mod
print((ans%mod))
if __name__ == '__main__':
main() | from itertools import accumulate
def main():
n=int(eval(input()))
a=list(map(int,input().split()))
aa=list(accumulate(a))
mod=10**9+7
ans=0
for i in range(n):
ans += a[i]*(aa[-1]-aa[i])%mod
print((ans%mod))
if __name__ == "__main__":
main() | p02572 |
def main():
from builtins import input, int, map
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(n - 1):
for j in range(i + 1, n):
ans += (a[i] * a[j]) % (10**9 + 7)
print((ans % (10**9 + 7)))
main() | 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 |
n = int(eval(input()))
a = list(map(int, input().split()))
allsum = 0
for i in range(n-1):
allsum += a[i] * sum(a[i+1:])
print((allsum % (10**9+7)))
| n = int(eval(input()))
a = list(map(int, input().split()))
"""
allsum = 0
for i in range(n-1):
allsum += a[i] * sum(a[i+1:])
print(allsum % (10**9+7))
"""
s, s2 = 0, 0
for i in range(n):
s += a[i]
s2 += a[i] * a[i]
print((((s*s - s2)//2) % (10**9+7)))
| p02572 |
mod = 10 ** 9 + 7
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):
prod = (a[i] * a[j]) % mod
ans += prod
ans %= mod
print(ans) | mod = 10 ** 9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
s = [0] * (n+1)
for i in range(n-1, 0, -1):
s[i] = (a[i] + s[i+1]) % mod
ans = 0
for i in range(n-1):
tmp = (a[i] * s[i+1]) % mod
ans += tmp
ans %= mod
print(ans) | p02572 |
import itertools
n = int(eval(input()))
a = list(map(int,input().split()))
cnt = 0
for i,j in itertools.combinations(a,2):
cnt += i*j
print((cnt % (10**9 + 7))) | import itertools
n = int(eval(input()))
a = list(map(int,input().split()))
ruisekiwa = [0] * n
cnt = 0
ruisekiwa[0] = a[0]
for i in range(1,n):
ruisekiwa[i] = ruisekiwa[i-1] + a[i]
for i in range(n):
cnt += a[i] * (ruisekiwa[-1] - ruisekiwa[i])
print((cnt % (10**9 + 7))) | p02572 |
#!/usr/bin/env python3
import sys
input=sys.stdin.readline
mod=10**9+7
n=int(eval(input()))
arr=list(map(int,input().split()))
ans=0
sums=sum(arr)
for val in arr:
ans+=(val*sums)%mod
ans-=(val*val)%mod
print(((ans*pow(2,mod-2,mod))%mod)) | #!/usr/bin/env python3
import sys
input=sys.stdin.readline
mod=10**9+7
n=int(eval(input()))
arr=list(map(int,input().split()))
ans=sum(arr)*sum(arr)
for val in arr:
ans-=(val*val)%mod
print(((ans*pow(2,-1,mod))%mod)) | p02572 |
import sys
def input():
return sys.stdin.readline()[:-1]
def main():
n = int(eval(input()))
a = list(map(int,input().split()))
ans = 0
for i in range(n):
ans = ans + a[i] * sum(a[i+1:])
print((ans % (10 ** 9 + 7)))
if __name__ == "__main__":
main() | import sys
def input():
return sys.stdin.readline()[:-1]
def main():
n = int(eval(input()))
a = list(map(int,input().split()))
s = sum(a)
ans = 0
for i in range(n):
s = s - a[i]
ans = ans + a[i] * s
print((ans % (10 ** 9 + 7)))
if __name__ == "__main__":
main() | p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
answer = 0
mod = 1000000007
for i in range(N-1):
total = sum(A[i+1:])
multi = ((A[i] % mod) * (total % mod)) % mod
answer = (answer + multi) % mod
print((str(answer))) | N = int(eval(input()))
A = list(map(int, input().split()))
answer = 0
a_sum = sum(A)
mod = 10**9+7
for i in range(N-1):
a_sum -= A[i]
answer += a_sum * A[i]
print((str(answer % mod))) | p02572 |
N = int(eval(input()))
A = list(map(int, input().split()))
answer = 0
mod = 1000000007
for i in range(N-1):
total = sum(A[i+1:])
multi = A[i] * total
answer += multi
print((str(answer % mod))) | N = int(eval(input()))
A = list(map(int, input().split()))
answer = 0
a_sum = sum(A)
mod = 10**9+7
for i in range(N-1):
a_sum -= A[i]
answer += a_sum * A[i]
print((str(answer % mod))) | p02572 |
def main():
mod = 10**9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(0, n-1):
for j in range(i+1, n):
ans = (ans + (a[i] * a[j])) % mod
print(ans)
if __name__ == '__main__':
main() | def main():
MOD = 10**9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
a_sum = sum(a)
ans = 0
for i in range(n):
ans += a[i] * (a_sum - a[i])
print((ans // 2 % MOD))
if __name__ == '__main__':
main() | p02572 |
def main():
MOD = 10**9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
a_sum = []
for i in range(n):
a_sum.append(sum(a[i+1:n]))
for i in range(n-1):
ans += a[i] * a_sum[i]
ans %= MOD
print(ans)
if __name__ == '__main__':
main() | def main():
MOD = 10**9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
a_sum = sum(a)
for i in range(n-1):
a_sum -= a[i]
ans += a[i] * a_sum
ans %= MOD
print(ans)
if __name__ == '__main__':
main() | p02572 |
import copy
N = int(eval(input()))
A = list(map(int,input().split()))
mod = 10**9+7
partial_sum = copy.deepcopy(A)
sum_now = A[N-1]
for j in range(N-2,-1,-1):
sum_now = int((sum_now+A[j])%mod)
partial_sum[j] = sum_now
res = 0
for i in range(N-1):
res = (res + (A[i]*partial_sum[i+1])%mod) %mod
print((int(res)))
| N = int(eval(input()))
#A = [int(x) for x in input().split()]
A = list(map(int, input().split()))
mod = 10**9+7
partial_sum = A.copy()
sum_now = A[N-1]
for j in range(N-2,-1,-1):
sum_now = int((sum_now+A[j])%mod)
partial_sum[j] = sum_now
res = 0
for i in range(N-1):
res = (res + (A[i]*partial_sum[i+1])%mod) %mod
print((int(res)))
| p02572 |
n=int(eval(input()))
l=list(map(int,input().split()))
s=0
for i in range(n-1):
for j in range(i+1,n):
s+=l[i]*l[j]
print((s%(10**9+7))) | n=int(eval(input()))
l=list(map(int,input().split()))
sum=sum(l)
s=0
for i in range(n):
s+=l[i]*(sum-l[i])
print((s//2%(10**9+7))) | p02572 |
import itertools
N = int(eval(input()))
A = list(map(int,(input().split())))
Asum = 0
c_list = list(itertools.combinations(A, 2))
for l in c_list:
Asum = Asum + l[0]*l[1]
print((Asum % (10**9+7))) | N = int(eval(input()))
A = list(map(int,(input().split())))
total = 0
result = 0
MOD = pow(10,9)+7
l = []
for i in range(N):
total += A[i]
l.append(total)#累積和
for i,num in enumerate(l):
temp = total-num #A[i+1]+A[i+2]+...+A[N]
result += temp*A[i]#A[i](A[i+1]+A[i+2]+...+A[N])の総和
print((result%MOD))
| p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
mod = 10**9+7
listsum = 0
for i in range(n-1):
for j in range(i+1,n):
listsum += a[i]*a[j]%mod
listsum = listsum%mod
print(listsum) | n = int(eval(input()))
a = list(map(int, input().split()))
mod = 10**9+7
listsum = sum(a)
kotae = 0
for i in range(n-1):
listsum -= a[i]
kotae += listsum*a[i]%mod
print((kotae%mod)) | p02572 |
mod = 10**9+7
n = int(eval(input()))
input_list = list(map(int,input().split()))
input_len = len(input_list)
temp = 0
for i in range(input_len):
for j in range(i+1,input_len):
temp = (temp+input_list[i]*input_list[j])%mod
print(temp) | mod = 10**9+7
n = int(eval(input()))
input_list = list(map(int,input().split()))
input_len = len(input_list)
remain_num = sum(input_list[1:])
remain_list = [remain_num]
for i in range(1,input_len):
remain_list.append(remain_list[i-1]-input_list[i])
temp = 0
for i in range(input_len):
temp = (temp+input_list[i]*remain_list[i])%mod
print(temp) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
sum = 0
for i in range(n-1):
sum_i = 0
for j in range(n-i-1):
sum_i += a[-(j+1)]
sum += (sum_i * a[i])
print((sum%((10 ** 9)+7))) | n = int(eval(input()))
a = list(map(int, input().split()))
sum_a = 0
sum_i = sum(a)
for i in range(n-1):
sum_i -= a[i]
sum_a += (a[i] * sum_i)
print((sum_a%((10 **9)+7))) | p02572 |
n=int(eval(input()))
i = list(map(int, input().split()))
ans=0
for k in range(n-1):
for j in range(k+1,n):
ans+=(i[k]*i[j])%(10**9+7)
ans=ans%(10**9+7)
print(ans)
| n=int(eval(input()))
i = list(map(int, input().split()))
m=sum(i)
ans=0
for k in range(n):
ans+=(i[k]*(m-i[k]))
ans=ans//2
ans=ans%(10**9+7)
print(ans) | p02572 |
import math
N = eval(input())
nums = [int(i) for i in input().split(' ')]
sum = 0
for i in range(len(nums)-1):
for ii in range(len(nums)-i-1):
sum += nums[i]*nums[i+ii+1]
sum = sum%(math.pow(10,9)+7)
print((int(sum)))
| N = eval(input())
a_list = [int(i) for i in input().split(' ')]
mod = 1000000007
sum_list = []
sum = 0
for i in a_list:
sum += i
sum_list.append(sum)
sum = 0
for idx, i in enumerate(a_list[:-1]):
sum += i*(sum_list[-1]-sum_list[idx])
print((sum%mod))
| p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(len(a)-1):
for j in range(i+1, len(a)):
ans += (a[i]*a[j])
ans = ans % ((10**9)+7)
print(ans) | n = int(eval(input()))
a = list(map(int, input().split()))
sm = sum(a)
ans = 0
for i in range(len(a)):
ans += a[i]*(sm-a[i])
sm = sm - a[i]
ans %= (10**9)+7
print(ans) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
for i in range(n-1):
ans += a[i]*sum(a[i+1:])
ans %= 10**9+7
print(ans) | n = int(eval(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 |
n = int(eval(input()))
a = list(map(int, input().split()))
ans = 0
mod = 10**9+7
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()))
ans = 0
mod = 10**9+7
S = sum(a)
for i in range(n-1):
S -= a[i]
ans += a[i]*S
ans %= mod
print(ans)
| p02572 |
def solve():
N = int(eval(input()))
A = list(map(int, input().split()))
sum_a = 0
for i in range(N-1):
for k in range(i+1,N):
sum_a += A[i] * A[k]
# print(sum_a)
ans = sum_a % 1000000007
print(ans)
if __name__ == "__main__":
solve()
| def solve():
N = int(eval(input()))
A = list(map(int, input().split()))
sum_a = 0
tmp = 0
for i in range(N-1):
tmp += A[i]
sum_a += tmp * A[i+1]
# print(sum_a)
ans = sum_a % 1000000007
print(ans)
if __name__ == "__main__":
solve()
| p02572 |
N = int(eval(input()))
data = input().split()
data = [int(s) for s in data]
num = 0
ans = 0
for i in range(N) :
num += data[i]
ans += (sum(data) - num) * data[i]
print((ans % 1000000007)) | N = int(eval(input()))
data = input().split()
data = [int(s) for s in data]
num = 0
ans = 0
sum = sum(data)
for i in range(N) :
num += data[i]
ans += (sum - num) * data[i]
print((ans % 1000000007)) | p02572 |
import math
import itertools
# 与えられた数値の桁数と桁値の総和を計算する.
def calc_digit_sum(num):
digits = sums = 0
while num > 0:
digits += 1
sums += num % 10
num //= 10
return digits, sums
n = int(eval(input()))
arr = list(map(int, input().split()))
MOD = 10 ** 9 + 7
answer = 0
for idx1 in range(len(arr) - 1):
for idx2 in range(idx1 + 1, len(arr)):
answer = (answer + (arr[idx1] * arr[idx2])) % MOD
print(answer) | n = int(eval(input()))
arr = list(map(int, input().split()))
mod = 10 ** 9 + 7
sums = sum(arr)
answer = 0
for num in arr:
sums -= num
answer = (answer + (sums * num)) % mod
print(answer) | p02572 |
#C - Sum of product of pairs
N = int(eval(input()))
A = list(map(int,input().split()))
SUM = 0
MOD = 1000000007
for i in range(N-1):
for j in range(i+1,N):
SUM = (SUM + (A[i] * A[j] % MOD) ) % MOD
# 出力
print(SUM)
| #C - Sum of product of pairs
N = int(eval(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 |
N = int(eval(input()))
l = list(map(int,input().split()))
s = 0
for i in range(len(l)-1):
for j in range(1,len(l)-i):
s = s + l[i]*l[i+j]
s = s%(pow(10,9)+7)
print(s) | N = int(eval(input()))
A = list(map(int,input().split()))
S = sum(A)
S2 = sum([x**2 for x in A])
print(((S**2-S2)//2%(1000000000+7)))
| p02572 |
n = int(eval(input()))
a = list(map(int,input().split()))
import itertools
ans = 0
result = []
for i in range(len(a)):
for j in range(i+1,len(a)):
if i < j:
ans += a[i] * a[j]
print((ans%(10 ** 9 + 7))) | n = int(eval(input()))
a = list(map(int,input().split()))
ans = 0
sum_a = sum(a)
for i in range(n):
ans += a[i] * (sum_a - a[i])
sum_a -= a[i]
print((ans%(10 ** 9 + 7))) | p02572 |
n = int(eval(input()))
nums = list(map(int, input().split()))
ans = 0
for i in range(n):
ans += nums[i] * sum(nums[i+1:])
print((ans % (10**9+7))) | n = int(eval(input()))
nums = list(map(int, input().split()))
ans = 0
s = sum(nums)
for i in range(n):
s -= nums[i]
ans += nums[i] * s
print((ans % (10**9+7))) | p02572 |
n = int(eval(input()))
A = list(map(int,input().split()))
s = [0]*n
for i in range(n):
s[i] = sum(A[i+1:])
tot = 0
for i in range(n-1):
tot += A[i]*s[i]
print((tot%(10**9+7))) | n = int(eval(input()))
A = list(map(int,input().split()))
a = A[::-1]
s = [0]*(n+1)
for i in range(n):
s[i+1] = s[i] + a[i]
s = s[:n]
s = s[::-1]
tot = 0
for i in range(n-1):
tot += A[i]*s[i]
print((tot%(10**9+7)))
| p02572 |
N = int(eval(input()))
A = [int(x) for x in input().split()]
mod = 10**9 + 7
a = 0
for i in range(0, N - 1):
for j in range(i + 1, N):
a += (A[i] * A[j])
print((a % mod)) | mod = 10**9 + 7
N = int(eval(input()))
A = [int(x) for x in input().split()]
S = sum(A) % mod
ans = 0
for i in range(N):
S -= A[i]
if S < 0: S += mod
ans += S * A[i]
ans %= mod
print(ans) | p02572 |
N = int(eval(input()))
X = list(map(int, input().split()))
p = 0
for n in range(N):
for m in range(n+1, N):
p += X[n]*X[m]
if p >= 10**9 + 7:
p = p % (10**9 + 7)
#while p >= 10**9 + 7:
#p -= 10**9 + 7
print(p) | N = int(eval(input()))
X = list(map(int, input().split()))
p = 0
s = sum(X)
for n in range(N):
s -= X[n]
s = s % (10**9 + 7)
p += s * X[n]
p = p % (10**9 + 7)
print(p) | p02572 |
import itertools
n = int(eval(input()))
li = list(map(int,input().split()))
asum = 0
newli = list(itertools.combinations(li,2))
for i in range(n*(n-1)//2):
asum += newli[i][0]*newli[i][1]
if asum >= 10**9 + 7:
asum = asum % (10**9 + 7)
print(asum) | n = int(eval(input()))
li = list(map(int,input().split()))
licumsum = 0
for i in range(n):
licumsum += li[i]
asum = 0
for i in range(n):
asum += li[i]*(licumsum - li[i])
if asum >= (10**9 + 7)*2:
asum = asum % ((10**9 + 7)*2)
if asum//2 >= 10**9 + 7:
print((asum//2-(10**9+7)))
else:
print((asum//2)) | p02572 |
N = int(eval(input()))
S = list(map(int, input().split(' ')))
prod=0
law=10**9+7
for i in range(N):
for j in range(i+1, N):
prod=prod+((S[i]%law)*(S[j]%law))%law
print((prod%law)) | N = int(eval(input()))
S = list(map(int, input().split(' ')))
prod=0
law=10**9+7
sumation=sum(S)
for i in range(N):
sumation=sumation-S[i]
prod=prod+(S[i]*sumation)%law
print((prod%law)) | p02572 |
N = int(eval(input()))
A = [int(a) for a in input().split()]
import itertools
sum = 0
for i, j in itertools.combinations(A, 2):
sum += i * j
print((sum % (10**9+7))) | N = int(eval(input()))
A = [int(a) for a in input().split()]
mod = 10**9 + 7
print((((sum(A)**2 - sum([i**2 for i in A]))//2) % mod)) | p02572 |
n = int(eval(input()))
a_int = list(map(int, input().split()))
squ = 0
num = 10 ** 9 + 7
for i in range(0, n-1):
for j in range(i+1, n):
squ += (a_int[i] * a_int[j]) % num
ans = squ % num
print(ans) | n = int(eval(input()))
a_int = list(map(int, input().split()))
squ = 0
num = 10 ** 9 + 7
a_sum = 0
for i_sum in range(1, n):
a_sum += a_int[i_sum]
for i in range(0, n-1):
squ += a_int[i] * a_sum
a_sum -= a_int[i+1]
ans = squ % num
print(ans) | p02572 |
import itertools
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]%mod)*(a[j]%mod)
print((ans%mod)) | n = int(eval(input()))
a = list(map(int,input().split()))
mod = 10**9 + 7
sum_a = sum(a)%mod
ans = 0
for i in range(n-1):
sum_a -= a[i]
ans += (a[i]*sum_a)%mod
print((ans%mod)) | p02572 |
#!/usr/bin/env python3
def main():
_ = int(eval(input()))
A = [int(x) for x in input().split()]
mod = 10 ** 9 + 7
lst = [sum(A)]
for j in A:
lst.append(lst[-1] - j)
ans = 0
for index, i in enumerate(A):
ans += i * lst[index + 1] % mod
print((ans % mod))
if __name__ == '__main__':
main()
| #!/usr/bin/env python3
def main():
_ = int(eval(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 |
n = int(eval(input()))
A = list(map(int, input().split()))
ans = 0
for i in range(n-1):
ans = (ans + A[i] * sum(A[i+1:])) % int(1e9 + 7)
print(ans)
| n = int(eval(input()))
A = list(map(int, input().split()))
s = sum(A)
ans = 0
for i in range(n-1):
s -= A[i]
ans = (ans + A[i] * s) % int(1e9 + 7)
print(ans)
| p02572 |
num = int(eval(input()))
input_line = input().split()
law = 10 ** 9 + 7
num_list = [int(input_line[i])%law for i in range(num)]
sigma = 0
for i in range(num):
num_a = num_list[i]
temp_sum = 0
for j in range(i+1,num):
temp_sum += num_list[j]
sigma += num_a * temp_sum
sigma %= law
print(sigma) | num = int(eval(input()))
input_line = input().split()
law = 10 ** 9 + 7
num_list = [int(input_line[i])%law for i in range(num)]
sigma = 0
temp_sum = 0
for j in range(num):
temp_sum += num_list[j]
for i in range(num):
num_a = num_list[i]
temp_sum -= num_a
sigma += num_a * temp_sum
sigma %= law
print(sigma) | p02572 |
N=int(eval(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)
| n = int(eval(input()))
a = list(map(int, input().split()))
mod = 10 ** 9 + 7
s = sum(a)
ans = 0
for i in a[:n - 1]:
s -= i
ans += s * i
ans %= 10 ** 9 + 7
print(ans)
| p02572 |
import sys
MOD = 10**9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
sum = 0
for index, i in enumerate(a[:n - 1]):
for j in a[index + 1:n]:
sum = (sum + (i * j)) % MOD
print(sum) | import sys
MOD = 10**9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
x = pow(sum(a), 2)
y = sum((a[i]**2 for i in range(n)))
sum = (x - y) // 2 % MOD
print(sum)
| p02572 |
N = int(eval(input()))
A = list(map(int,input().split()))
Ans = 0
S = []
for j in range(N-1):
S.append(sum(A[:N-j-1]))
for i in range(N-1):
Ans += A[N-i-1]*S[i]
print((Ans%((10**9)+7))) | N = int(eval(input()))
A = list(map(int,input().split()))
Ans = 0
S = sum(A)
for i in range(N-1):
S -= A[N-i-1]
Ans += A[N-i-1]*S
print((Ans%((10**9)+7))) | 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 %= 1000000007
print(ans)
| n = int(eval(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 |
N = int(eval(input()))
A = [int(s) for s in input().split()]
mod = 10**9+7
seki_list = []
for i in range(N-1):
seki = sum(A[i+1:])
seki_list.append(seki)
ans = 0
for i in range(N-1):
seki = A[i]*seki_list[i]
ans += seki
print((ans % mod)) | N = int(eval(input()))
A = [int(s) for s in input().split()]
mod = 10**9+7
wa = 0
wa_list = []
for i in range(N)[::-1]:
if i == 0:
break
wa += A[i]
wa_list.append(wa)
wa_list.reverse()
ans = 0
for i in range(N-1):
seki = A[i]*wa_list[i]
ans += seki
print((ans % mod)) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
s = 0
for i in range(len(a)-1):
s_tmp = sum(a[i+1:len(a)])
s += a[i] * s_tmp
print((s % 1000000007)) | n = int(eval(input()))
s = 0
a = list(map(int, input().split()))
sum_tmp = sum(a[1:len(a)])
for i in range(len(a)-1):
s += a[i] * sum_tmp
sum_tmp -= a[i + 1]
print((s % 1000000007)) | p02572 |
mod=1000000007
n=int(eval(input()))
x=list(map(int,input().split()))
ans=0
for i in range(n):
for j in range(i+1,n):
ans+=(x[i]*x[j])%mod
print(((ans)%mod))
| mod=1000000007
n=int(eval(input()))
x=list(map(int,input().split()))
cl=[1]
for i in range(1,n):
cl.append(cl[i-1]+x[i])
sum=0
for i in range(n-1):
sum+= x[i]*(cl[n-1]-cl[i])
sum%=mod
print(sum)
| p02572 |
import sys
read = sys.stdin.readline
import time
from heapq import heappush, heappop, heapify
import math
import itertools as it
from collections import deque
def inp():
return int(input())
def inpl():
return list(map(int, input().split()))
start_time = time.perf_counter()
# ------------------------------
mod = 10**9 + 7
N = inp()
A = inpl()
wa = 0
for i in range(0, N - 1):
for j in range(i+1, N):
wa = (wa + A[i] * A[j]) % mod
print(wa)
# -----------------------------
end_time = time.perf_counter()
print('time:', end_time-start_time, file=sys.stderr)
| import sys
read = sys.stdin.readline
import time
from heapq import heappush, heappop, heapify
import math
import itertools as it
from collections import deque
def inp():
return int(input())
def inpl():
return list(map(int, input().split()))
start_time = time.perf_counter()
# ------------------------------
mod = 10**9 + 7
N = inp()
A = inpl()
wa = 0
sm = A[0]
for i in range(1, N):
wa = (wa + sm * A[i]) % mod
sm = (sm + A[i]) % mod
print(wa)
# -----------------------------
end_time = time.perf_counter()
print('time:', end_time-start_time, file=sys.stderr)
| p02572 |
def main():
n = int(eval(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_sum - a_cum[i+1]) % mod
ans %= mod
print(ans)
if __name__ == '__main__':
main() | def main():
n = int(eval(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 |
def main():
N = int(eval(input()))
A = list(map(int, input().split()))
mod = 10 ** 9 + 7
A_mod = [a % mod for a in A]
ans = 0
for i in range(N-1):
sum_mod = sum(A_mod[i+1:]) % mod
mul_mod = (A_mod[i] * sum_mod) % mod
ans = (ans + mul_mod) % mod
print(ans)
if __name__ == '__main__':
main()
| def main():
N = int(eval(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 |
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]
a =10**9+7
print((sum%a)) | N=int(eval(input()))
A =list(map(int,input().split()))
S =(sum(A))**2
for i in A:
S-=i**2
a =10**9+7
print(((S//2)%a)) | 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 += A[i] * A[j]
ans = sum % (10**9 + 7)
print(ans)
| N = int(eval(input()))
A = list(map(int, input().split()))
sum_a = 0
sum = 0
for i in range(N):
sum_a += A[i]
for i in range(N):
sum_a -= A[i]
sum += A[i] * sum_a
ans = sum % (10**9 + 7)
print(ans)
| p02572 |
#!/usr/bin/env python3
n=int(eval(input())) #->n=5
ai=list(map(int,input().split())) #->nl=[1,2,-,n]
temp = 0
for i in range(n-1):
for j in range(i+1,n):
temp = temp + ai[i]*ai[j]
temp = temp % (10**9+7)
print(temp)
| #!/usr/bin/env python3
n=int(eval(input())) #->n=5
a=list(map(int,input().split())) #->nl=[1,2,-,n]
mod=int(1e9+7)
# Accumulate
pre=[0]*n
pre[0]=a[0]
for i in range(1,n): pre[i]=pre[i-1]+a[i]
ans=0
for i in range(1,n): ans=(ans+(a[i-1]*(pre[n-1]-pre[i-1]))%mod)%mod
print(ans)
| p02572 |
N=int(eval(input()))
A=list(map(int, input().split()))
MOD=7+10**9
ans=0
for i in range(len(A)-1):
for j in range(i+1,len(A)):
ai= A[i] % MOD
aj= A[j] % MOD
ans = ans +ai*aj % MOD
print((ans%MOD)) | N=int(eval(input()))
A=list(map(int, input().split()))
MOD=7+10**9
SUM=sum(A)
ans=0
for i in range(N-1):
SUM-=A[i]
ans += A[i]*SUM %MOD
print((ans %MOD)) | p02572 |
n = int(eval(input()))
ls = list(map(int,input().split()))
di = [0]*(n+1)
mod = 10**9+7
ans = 0
for i in range(1,n+1):
di[i] = di[i-1] + ls[i-1]
for j in range(n-1):
ans += ls[j]*(di[n]-di[j+1]) % mod
print((ans%mod)) | n = int(eval(input()))
mod = 10**9+7
ls = list(map(int,input().split()))
di = [i**2 for i in ls]
print(((((sum(ls)**2)-(sum(di)))//2)%mod)) | p02572 |
N = int(eval(input()))
L = list(map(int, input().split()))
Ans = 0
for i in range(len(L)):
for j in range(i+1,len(L)):
#print(L[i] * L[j])
Ans += (L[i] * L[j])%(10**9+7)
#Ans += L[i] * L[j]
#if Ans >= 10**9+7:
#Ans = Ans%(10**9+7)
Ans = Ans%(10**9+7)
print(Ans) | N = int(eval(input()))
L = list(map(int, input().split()))
Ans = 0
sum_L = L[0]
l = len(L)
for i in L[1:]:
Ans += sum_L*i%(10**9+7)
sum_L += i
Ans = Ans%(10**9+7)
print(Ans) | p02572 |
import itertools
n = int(eval(input()))
a = list(map(int,input().split()))
ans = 0
m = 10**9 + 7
for item in itertools.combinations(a, 2):
ans += item[0] * item[1]
print((ans % m)) | n = int(eval(input()))
a = list(map(int, input().split()))
c = 10 ** 9 + 7
ans = 0
s = 0
for i in range(n-1, -1, -1):
ans += s * a[i]
s += a[i]
print((ans % c)) | p02572 |
from collections import deque,defaultdict,Counter
from heapq import heapify,heappop,heappush,heappushpop
from copy import copy,deepcopy
from itertools import product,permutations,combinations,combinations_with_replacement
from bisect import bisect_left,bisect_right
from math import sqrt,gcd,ceil,floor,factorial
# from fractions import gcd
from functools import reduce
from pprint import pprint
from statistics import mean,median,mode
import sys
sys.setrecursionlimit(10 ** 6)
INF = float('inf')
def mycol(data,col):
return [ row[col] for row in data ]
def mysort(data,col,reverse=False):
data.sort(key=lambda x:x[col],reverse=revese)
return data
def mymax(data):
M = -1*float('inf')
for i in range(len(data)):
m = max(data[i])
M = max(M,m)
return M
def mymin(data):
m = float('inf')
for i in range(len(data)):
M = min(data[i])
m = min(m,M)
return m
def mycount(ls,x):
# lsはソート済みであること
l = bisect_left(ls,x)
r = bisect_right(ls,x)
return (r-l)
def mydictvaluesort(dictionary):
return sorted( list(dictionary.items()), key=lambda x:x[1] )
def mydictkeysort(dictionary):
return sorted( list(dictionary.items()), key=lambda x:x[0] )
def myoutput(ls,space=True):
if space:
if len(ls)==0:
print(' ')
elif type(ls[0])==str:
print((' '.join(ls)))
elif type(ls[0])==int:
print((' '.join(map(str,ls))))
else:
print('Output Error')
else:
if len(ls)==0:
print('')
elif type(ls[0])==str:
print((''.join(ls)))
elif type(ls[0])==int:
print((''.join(map(str,ls))))
else:
print('Output Error')
def I():
return int(eval(input()))
def MI():
return list(map(int,input().split()))
def RI():
return list(map(int,input().split()))
def CI(n):
return [ int(eval(input())) for _ in range(n) ]
def LI(n):
return [ list(map(int,input().split())) for _ in range(n) ]
def S():
return eval(input())
def MS():
return input().split()
def RS():
return list(eval(input()))
def CS(n):
return [ eval(input()) for _ in range(n) ]
def LS(n):
return [ list(eval(input())) for _ in range(n) ]
# ddict = defaultdict(lambda: 0)
# ddict = defaultdict(lambda: 1)
# ddict = defaultdict(lambda: int())
# ddict = defaultdict(lambda: list())
# ddict = defaultdict(lambda: float())
mod = 10**9 + 7
n = I()
a = RI()
s = 0
for i in range(n-1):
for j in range(i+1,n):
s += (a[i]*a[j]) % mod
print((s%mod)) | from collections import deque,defaultdict,Counter
from heapq import heapify,heappop,heappush,heappushpop
from copy import copy,deepcopy
from itertools import product,permutations,combinations,combinations_with_replacement
from bisect import bisect_left,bisect_right
from math import sqrt,gcd,ceil,floor,factorial
# from fractions import gcd
from functools import reduce
from pprint import pprint
from statistics import mean,median,mode
import sys
sys.setrecursionlimit(10 ** 6)
INF = float('inf')
mod = 10**9 + 7
def mycol(data,col):
return [ row[col] for row in data ]
def mysort(data,col,reverse=False):
data.sort(key=lambda x:x[col],reverse=revese)
return data
def mymax(data):
M = -1*float('inf')
for i in range(len(data)):
m = max(data[i])
M = max(M,m)
return M
def mymin(data):
m = float('inf')
for i in range(len(data)):
M = min(data[i])
m = min(m,M)
return m
def mycount(ls,x):
# lsはソート済みであること
l = bisect_left(ls,x)
r = bisect_right(ls,x)
return (r-l)
def mydictvaluesort(dictionary):
return sorted( list(dictionary.items()), key=lambda x:x[1] )
def mydictkeysort(dictionary):
return sorted( list(dictionary.items()), key=lambda x:x[0] )
def myoutput(ls,space=True):
if space:
if len(ls)==0:
print(' ')
elif type(ls[0])==str:
print((' '.join(ls)))
elif type(ls[0])==int:
print((' '.join(map(str,ls))))
else:
print('Output Error')
else:
if len(ls)==0:
print('')
elif type(ls[0])==str:
print((''.join(ls)))
elif type(ls[0])==int:
print((''.join(map(str,ls))))
else:
print('Output Error')
def I():
return int(eval(input()))
def MI():
return list(map(int,input().split()))
def RI():
return list(map(int,input().split()))
def CI(n):
return [ int(eval(input())) for _ in range(n) ]
def LI(n):
return [ list(map(int,input().split())) for _ in range(n) ]
def S():
return eval(input())
def MS():
return input().split()
def RS():
return list(eval(input()))
def CS(n):
return [ eval(input()) for _ in range(n) ]
def LS(n):
return [ list(eval(input())) for _ in range(n) ]
# ddict = defaultdict(lambda: 0)
# ddict = defaultdict(lambda: 1)
# ddict = defaultdict(lambda: int())
# ddict = defaultdict(lambda: list())
# ddict = defaultdict(lambda: float())
n = I()
a = RI()
s = sum(a)
ls = []
for i in range(n):
s -= a[i]
ls.append(s)
# print(ls)
ans = 0
for i in range(n):
ans += a[i]*ls[i] % mod
print((ans%mod)) | p02572 |
N = int(eval(input()))
a = [int(s) for s in input().split()]
ans = int(0)
temp = int(0)
MOD = int(1000000007)
for i in range(N-1):
temp = sum(a[i+1:N])
temp = temp % MOD
temp = temp * a[i]
temp = temp % MOD
ans += temp
ans = ans % MOD
print(ans) | N = int(eval(input()))
a = [int(s) for s in input().split()]
ans = int(0)
temp = int(0)
MOD = int(1000000007)
sumari = sum(a)
for i in range(N-1):
sumari = sumari - a[i]
temp = sumari % MOD
temp = temp * a[i]
temp = temp % MOD
ans += temp
ans = ans % MOD
print(ans) | 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()))
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 |
import itertools
N = int(eval(input()))
A = [int(n) for n in input().split()]
ans = 0
m = 1000000007
for x, y in itertools.combinations(A, 2):
ans += x * y
print((ans % m))
| N = int(eval(input()))
A = list(map(int, input().split()))
ans = 0
m = 1000000007
s = 0
for i in range(N):
ans += A[i] * s
s += A[i]
print((ans % m))
| p02572 |
n = int(eval(input()))
li = list(map(int,input().split()))
mo = 10**9 + 7
ans = 0
for i in range(len(li)):
for j in range(i+1,len(li)):
ans+=li[i]*li[j]
print((ans%mo)) | n = int(eval(input()))
li = list(map(int,input().split()))
mo = 10**9 + 7
ans = 0
su = li[0]
for i in range(1,len(li)):
ans += li[i]*su
su+=li[i]
print((ans % mo)) | p02572 |
import itertools
N = int(eval(input()))
A = list(map(int, input().split()))
M = 10**9+7
result = 0
for itr in itertools.combinations(A,2):
result = (result + (itr[0]*itr[1])%M)%M
print(result) | N = int(eval(input()))
A = list(map(int, input().split()))
M = 10**9+7
ruisekiwa = [0]*N
wa = sum(A)%M
result = 0
for i in range(N):
wa -= A[i]
result = (result+(A[i]*wa)%M)%M
print(result) | p02572 |
#!/usr/bin/env python3
# from typing import Optional
# from typing import List
# from typing import Dict
# from typing import Tuple
# from typing import Sequence
def main():
N = int(eval(input()))
A = list([int(x) for x in input().split()])
sum = 0
mod = 1000000000 + 7
for i in range(N - 1):
for j in range(i + 1, N):
sum += A[i] * A[j]
sum = sum % mod
print(sum)
if __name__ == "__main__":
main()
| #!/usr/bin/env python3
# from typing import Optional
# from typing import List
# from typing import Dict
# from typing import Tuple
# from typing import Sequence
def main():
N = int(eval(input()))
A = list([int(x) for x in input().split()])
sum = 0
mod = 1000000000 + 7
sumJ = 0
for j in range(N):
sumJ += A[j]
for i in range(N - 1):
sumJ -= A[i]
sum += A[i] * sumJ
sum = sum % mod
print(sum)
if __name__ == "__main__":
main()
| p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
MOD = 10**9+7
ans = 0
def dfs(A, start):
global ans
if len(A) == 2:
ans += ((A[0]*A[1])%MOD)
return
else:
for i in range(start, len(a)):
A.append(a[i])
dfs(A, i+1)
A.pop()
dfs([], 0)
print((ans%MOD)) | n = int(eval(input()))
a = list(map(int, input().split()))
MOD = 10**9+7
acc = [0]
ans = 0
for i in a:
acc.append(acc[-1]+i)
acc = acc[1:]
for i, v in enumerate(a):
ans += (v*(acc[-1]-acc[i]))%MOD
print((ans%MOD)) | p02572 |
n = int(eval(input()))
x = list(map(int, input().split()))
sum = 0
for i in range(n):
for j in range(i):
sum += x[i]*x[j]
print((sum % (pow(10,9)+7))) | n = int(eval(input()))
lst = list(map(int, input().split()))
s = (sum(lst)**2 - sum([z**2 for z in lst]))//2
print((s % (pow(10,9)+7))) | p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
#mod_a = [i%(10**9 + 7) for i in a]
res = 0
for i in range(0, len(a)-1):
for j in range(i+1, len(a)):
res += (a[i]*a[j])%(10**9 + 7)
print((res%(10**9 + 7)))
| n = int(eval(input()))
a = list(map(int, input().split()))
#mod_a = [i%(10**9 + 7) for i in a]
res = 0
sum_a = sum(a)
b = 0
t = 0
for i in range(0, len(a)-1):
t = a[i]
b += a[i]
res += (sum_a - b)*t%(10**9 + 7)
print((res%(10**9 + 7)))
| p02572 |
from itertools import product, combinations
n = int(eval(input()))
a = list(map(int, input().split()))
result = 0
for x, y in combinations(a, 2):
result += x * y
print((result % (10 ** 9 + 7))) | from itertools import accumulate
MOD = 10 ** 9 + 7
n = int(eval(input()))
a = list(map(int, input().split()))
suffix_sum = list(accumulate(a[::-1]))[::-1]
req_arr = [x - y for x, y in zip(suffix_sum, a)]
result = sum([(x * y) % MOD for x, y in zip(req_arr, a)])
print((result % MOD))
| p02572 |
n = int(eval(input()))
S = [int(a) for a in input().split()]
divisor = 10**9 + 7
tot = 0
a,b = 0,0
for i in range(n-1):
#b = 0
b = sum(S[i+1:n]) % divisor
#for j in range(i+1,n):
# b += S[j]
# if b >= divisor:
# b = b % divisor
a = S[i]
#tot += multmod(a,b,divisor)
tot += a*b % divisor
#if tot >= divisor:
# tot = tot % divisor
tot = tot % divisor
print(tot) | def multmod(a,b,m):
ans = 0
a = a % m
while b:
if (b & 1): # odd
ans = (ans + a) % m
a = (2 * a) % m
b >>= 1 # b = b / 2
return ans
n = int(eval(input()))
S = [int(a) for a in input().split()]
divisor = 10**9 + 7
tot = 0
a,b = 0,0
arr_sum = sum(S) #% divisor
arr_ssq = arr_sum*arr_sum #% divisor
isq_sum = 0
for i in range(n):
isq_sum += S[i]*S[i] #% divisor
#isq_sum = isq_sum % divisor
tot = (arr_ssq - isq_sum)//2 % divisor
print(tot) | p02572 |
N = int(eval(input()))
A = list(map(int,input().split()))
P = 10**9+7
ans = 0
for i in range(N):
temp = 0
for j in range(i+1,N):
temp += A[j]
temp *= A[i]
ans += temp%P
print((ans%P)) | N = int(eval(input()))
A = list(map(int,input().split()))
P = 10**9+7
ans = 0
S = sum(A)
for i in range(N):
S -= A[i]
ans += A[i]*S%P
print((ans%P)) | p02572 |
import math
import sys,collections
from sys import stdin, stdout
#MAXN = 10000001
def get_ints(): return list(map(int, sys.stdin.readline().strip().split()))
def get_array(): return list(map(int, sys.stdin.readline().strip().split()))
def get_string(): return sys.stdin.readline().strip()
def input(): return sys.stdin.readline().strip()
#spf = [0 for i in range(MAXN)]
def file():
sys.stdin = open('input.py', 'r')
sys.stdout = open('output.py', 'w')
def is_subsequence(x, y):
"""Test whether x is a subsequence of y"""
x = list(x)
for letter in y:
if x and x[0] == letter:
x.pop(0)
return not x
def sieve():
spf[1] = 1
for i in range(2, MAXN):
spf[i] = i
for i in range(4, MAXN, 2):
spf[i] = 2
for i in range(3, mt.ceil(mt.sqrt(MAXN))):
if (spf[i] == i):
for j in range(i * i, MAXN, i):
if (spf[j] == j):
spf[j] = i
def getFactorization(x):
ret = list()
while (x != 1):
ret.append(spf[x])
x = x // spf[x]
return ret
def getFloor(A, x):
(left, right) = (0, len(A) - 1)
ind,floor = -1,-1
while left <= right:
mid = (left + right) // 2
'''if A[mid] == x:
return mid'''
if x < A[mid]:
right = mid - 1
else:
floor = A[mid]
ind=mid
left = mid + 1
return ind
def check(st) :
# Compute sum of digits
n = len(st)
digitSum = 0
for i in range(0,n) :
digitSum = digitSum + (int)(st[i])
# Check if sum of digits
# is divisible by 9.
return (digitSum % 9 == 0)
def isPowerOfTwo(n):
if (n == 0):
return False
while (n != 1):
if (n % 2 != 0):
return False
n = n // 2
return True
def kitte(n):
c=0
while(n!=0):
n=n//2
c+=1
return c
def aa(b,c):
m=min(b,c)
b-=m
c-=m
if(c>0 and b>0):
return(m+((b+c)//3))
else:
return(m)
def bb(a,c):
m=min(a,c)
a-=m
c-=m
if(c>0 and a>0):
return(m+((a+c)//3))
else:
return(m)
def cc(b,a):
m=min(b,a)
b-=m
a-=m
if(a>0 and b>0):
return(m+((b+a)//3))
else:
return(m)
#file()
#sieve()
mod=(10**9)+7
def main():
n=int(eval(input()))
l=get_array()
s=0
#n=len(l)
for i in range(n):
for j in range(i+1,n):
a=l[i]%mod
b=l[j]%mod
s+=(a*b)%mod
print((s%mod))
if __name__ == '__main__':
main() | import math
import sys,collections
from sys import stdin, stdout
#MAXN = 10000001
def get_ints(): return list(map(int, sys.stdin.readline().strip().split()))
def get_array(): return list(map(int, sys.stdin.readline().strip().split()))
def get_string(): return sys.stdin.readline().strip()
def input(): return sys.stdin.readline().strip()
#spf = [0 for i in range(MAXN)]
def file():
sys.stdin = open('input.py', 'r')
sys.stdout = open('output.py', 'w')
def is_subsequence(x, y):
"""Test whether x is a subsequence of y"""
x = list(x)
for letter in y:
if x and x[0] == letter:
x.pop(0)
return not x
def sieve():
spf[1] = 1
for i in range(2, MAXN):
spf[i] = i
for i in range(4, MAXN, 2):
spf[i] = 2
for i in range(3, mt.ceil(mt.sqrt(MAXN))):
if (spf[i] == i):
for j in range(i * i, MAXN, i):
if (spf[j] == j):
spf[j] = i
def getFactorization(x):
ret = list()
while (x != 1):
ret.append(spf[x])
x = x // spf[x]
return ret
def getFloor(A, x):
(left, right) = (0, len(A) - 1)
ind,floor = -1,-1
while left <= right:
mid = (left + right) // 2
'''if A[mid] == x:
return mid'''
if x < A[mid]:
right = mid - 1
else:
floor = A[mid]
ind=mid
left = mid + 1
return ind
def check(st) :
# Compute sum of digits
n = len(st)
digitSum = 0
for i in range(0,n) :
digitSum = digitSum + (int)(st[i])
# Check if sum of digits
# is divisible by 9.
return (digitSum % 9 == 0)
def isPowerOfTwo(n):
if (n == 0):
return False
while (n != 1):
if (n % 2 != 0):
return False
n = n // 2
return True
def kitte(n):
c=0
while(n!=0):
n=n//2
c+=1
return c
def aa(b,c):
m=min(b,c)
b-=m
c-=m
if(c>0 and b>0):
return(m+((b+c)//3))
else:
return(m)
def bb(a,c):
m=min(a,c)
a-=m
c-=m
if(c>0 and a>0):
return(m+((a+c)//3))
else:
return(m)
def cc(b,a):
m=min(b,a)
b-=m
a-=m
if(a>0 and b>0):
return(m+((b+a)//3))
else:
return(m)
def findProductSum(A, n):
# calculating array sum (a1 + a2 ... + an)
array_sum = 0
for i in range(0, n, 1):
array_sum = (array_sum + A[i])
# calcualting square of array sum
# (a1 + a2 + ... + an)^2
array_sum_square = (array_sum * array_sum)
# calcualting a1^2 + a2^2 + ... + an^2
individual_square_sum = 0
for i in range(0, n, 1):
individual_square_sum += (A[i] * A[i])
# required sum is (array_sum_square -
# individual_square_sum) / 2
return (array_sum_square -
individual_square_sum) // 2
#file()
#sieve()
mod=(10**9)+7
def main():
n=int(eval(input()))
l=get_array()
s=0
s=findProductSum(l,n)
print((s%mod))
if __name__ == '__main__':
main()
| p02572 |
n = int(eval(input()))
a = list(map(int, input().split()))
s = 0
for i in range(n - 1):
for j in range(i + 1, n):
s += a[i] * a[j]
s %= 10 ** 9 + 7
print(s) | n = int(eval(input()))
a = list(map(int, input().split()))
s = 0
for i in range(n):
s += a[i]
tr = 0
for i in range(n):
tr += a[i] ** 2
a2 = s ** 2 - tr
a = a2 // 2
a %= 10 ** 9 + 7
print(a) | p02572 |
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