hacktober2021/Number of pairs.cpp at main · GitDeveloper007/hacktober2021 · GitHub

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/*
Given two arrays X and Y of positive integers, find the number of pairs such that xy > yx (raised to power of) where x is an element from X and y is an element from Y.

Example 1:

Input:
M = 3, X[] = [2 1 6]
N = 2, Y[] = [1 5]
Output: 3
Explanation:
The pairs which follow xy > yx are
as such: 21 > 12,  25 > 52 and 61 > 16 .
Example 2:

Input:
M = 4, X[] = [2 3 4 5]
N = 3, Y[] = [1 2 3]
Output: 5
Explanation:
The pairs for the given input are
21 > 12 , 31 > 13 , 32 > 23 , 41 > 14 ,
51 > 15 .

Your Task:
This is a function problem. You only need to complete the function countPairs() that takes X, Y, M, N as parameters and returns the total number of pairs.

Expected Time Complexity: O((N + M)log(N)).
Expected Auxiliary Space: O(1).

Constraints:
1 ≤ M, N ≤ 105
1 ≤ X[i], Y[i] ≤ 103
*/

long long countPairsBruteForce(long long X[], long long Y[],
							long long m, long long n)
{
	long long ans = 0;

	for (int i = 0; i < m; i++)
		for (int j = 0; j < n; j++)
			if (pow(X[i], Y[j]) > pow(Y[j], X[i]))
				ans++;
	return ans;
}