Buggy python submission (verdict: Time Limit Exceeded):
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(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)


Fixed submission:
n = int(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)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools
from heapq import heapify, heappop, heappush, heappushpop

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(input())
l = list(map(int, input().split()))
mod = 1000000007
for a,b in itertools.combinations(l, 2):
    q.push(((a % mod) * (b % mod)) % mod)
print(sum(heap) % mod)


Fixed submission:
n = int(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)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools
from heapq import heapify, heappop, heappush, heappushpop

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(input())
l = tuple(map(int, input().split()))
total = 0
mod = 1000000007
L = itertools.combinations(l, 2)
for a,b in L:
    num = ((a % mod) * (b % mod)) % mod
    q.push(num)
print(sum(heap) % mod)


Fixed submission:
n = int(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)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools
from heapq import heappush, heappop
from random import randint
from time import time

class PriorityQueue(object):
    def __init__(self):
        self.queue = []
    def push(self, value):
        heappush(self.queue, value)
    def pop(self):
        return heappop(self.queue)
    def __len__(self):
        return len(self.queue)
    def __contains__(self, item):
        return item in self.queue
    #...
queue = PriorityQueue()
n = int(input())
l = tuple(map(int, input().split()))
total = 0
mod = 1000000007
L = itertools.combinations(l, 2)
for a,b in L:
    num = ((a % mod) * (b % mod)) % mod
    queue.push(num)
while len(queue) > 0:
    total += queue.pop()
print(total % mod)


Fixed submission:
n = int(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)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools

n = int(input())
l = tuple(map(int, input().split()))
total = []
mod = 1000000007
L = itertools.combinations(l, 2)
for a,b in L:
    num = ((a % mod) * (b % mod)) % mod
    total.append(num)
print(sum(total) % mod)

Fixed submission:
n = int(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)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools

n = int(input())
l = tuple(map(int, input().split()))
total = 0
mod = 1000000007
L = itertools.combinations(l, 2)
for a,b in L:
    total += ((a % mod) * (b % mod)) % mod
print(total % mod)

Fixed submission:
n = int(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)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools

n = int(input())
l = list(map(int, input().split()))
total = 0
mod = 1000000007
L = itertools.combinations(l, 2)
for a,b in L:
    a = a % mod
    b = b % mod
    sum = (a * b) % mod
    total += sum
print(total % mod)

Fixed submission:
n = int(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)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools

n = int(input())
l = list(map(int, input().split()))
total = 0
mod = 1000000007
L = itertools.combinations(l, 2)
for a,b in L:
    total += ((a % mod) * (b % mod)) % mod
print(total % mod)

Fixed submission:
n = int(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)

Buggy python submission (verdict: Time Limit Exceeded):
import itertools
n = int(input())
l = list(map(int, input().split()))
total = 0
mod = 1000000007
ans = 0
for a,b in itertools.combinations(l, 2):
    total += ((a % mod) * (b % mod)) % mod
print(total % mod)

Fixed submission:
n = int(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)