How to find the maximum product of two elements in a list?

Question

I was trying out a problem on hackerrank contest for fun, and there came this question. I used itertools for this, here is the code:

import itertools

l = []

for _ in range(int(input())):
    l.append(int(input()))


max = l[0] * l[len(l)-1]

for a,b in itertools.combinations(l,2):
    if max < (a*b):
        max = (a*b)
print(max)

Is their any other efficient way than this? As I am getting time out error on some test cases which I cant access (as its a small contest).

Answer 1

Iterate over the list and find the following:

Largest Positive number(a)

Second Largest Positive number(b)

Largest Negative number(c)

Second Largest Negative number(d)

Now, you will be able to figure out the maximum value upon multiplication, either a*b or c*d