# Javascript Program for Pairs such that one is a power multiple of other

• Last Updated : 19 Jan, 2022

You are given an array A[] of n-elements and a positive integer k. Now you have find the number of pairs Ai, Aj such that Ai = Aj*(kx) where x is an integer.
Note: (Ai, Aj) and (Aj, Ai) must be count once.
Examples :

```Input : A[] = {3, 6, 4, 2},  k = 2
Output : 2
Explanation : We have only two pairs
(4, 2) and (3, 6)

Input : A[] = {2, 2, 2},   k = 2
Output : 3
Explanation : (2, 2), (2, 2), (2, 2)
that are (A1, A2), (A2, A3) and (A1, A3) are
total three pairs where Ai = Aj * (k^0) ```

To solve this problem, we first sort the given array and then for each element Ai, we find number of elements equal to value Ai * k^x for different value of x till Ai * k^x is less than or equal to largest of Ai.
Algorithm:

```    // sort the given array
sort(A, A+n);

// for each A[i] traverse rest array
for (int i=0; i

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Javascript

`<script> `
` `
`// Javascript Program to find pairs count `
` `
`// function to count the required pairs `
`function` `countPairs(A, n, k) { `
`  ``var` `ans = 0; `
`   `
`  ``// sort the given array `
`  ``A.sort((a,b)=>a-b) `
` `
`  ``// for each A[i] traverse rest array `
`  ``for` `(``var` `i = 0; i < n; i++) { `
`    ``for` `(``var` `j = i + 1; j < n; j++) { `
` `
`      ``// count Aj such that Ai*k^x = Aj `
`      ``var` `x = 0; `
` `
`      ``// increase x till Ai * k^x <= largest element `
`      ``while` `((A[i] * Math.pow(k, x)) <= A[j]) { `
`        ``if` `((A[i] * Math.pow(k, x)) == A[j]) { `
`          ``ans++; `
`          ``break``; `
`        ``} `
`        ``x++; `
`      ``} `
`    ``} `
`  ``} `
`  ``return` `ans; `
`} `
` `
`// driver program `
`var` `A = [3, 8, 9, 12, 18, 4, 24, 2, 6]; `
`var` `n = A.length; `
`var` `k = 3; `
`document.write( countPairs(A, n, k)); `
` `
`// This code is contributed by rutvik_56. `
`</script>`

Output : 6 Please refer complete article on Pairs such that one is a power multiple of other for more details!My Personal Notes
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