Given an array of size N, find the number of distinct pairs {i, j} (i != j) in the array such that the sum of a[i] and a[j] is greater than 0.
Example 1:
Input: N = 3, a[] = {3, -2, 1}
Output: 2
Explanation: {3, -2}, {3, 1} are two
possible pairs.
Example 2:
Input: N = 4, a[] = {-1, -1, -1, 0}
Output: 0
Explanation: There are no possible pairs.
Your Task:
You don't need to read input or print anything. Complete the function ValidPair() which takes the array a[ ] and size of array N as input parameters and returns the count of such pairs.
Expected Time Complexity: O(N * Log(N))
Expected Auxiliary Space: O(1)
Constraints:
1 ≤ N ≤ 10^{5}
-10^{4} ≤ a[i] ≤ 10^{4}

见题面

见题面