Suppose we have a list of positive numbers nums, we have to find the number of valid pairs of indices (i, j), where i < j, and nums[i] + nums[j] is an odd number.
So, if the input is like [5, 4, 6], then the output will be 2, as two pairs are [5,4] and [5,6], whose sum are odd.
To solve this, we will follow these steps −
Let us see the following implementation to get better understanding −
class Solution: def solve(self, nums): e=[i for i in nums if i%2==0] return (len(nums)-len(e))*len(e) nums = [5, 4, 6] ob = Solution() print(ob.solve(nums))
[5, 4, 6]