# Magic Pairs Codechef Solution|Problem Code: ALEXNUMB

Hello coders, today we are going to solve Magic Pairs Codechef Solution|Problem Code: ALEXNUMB.

### Problem

Alexandra has some distinct integer numbers a1,a2…an. Count number of pairs (i,j) such that:1≤ i ≤ n1≤ j ≤ nai < aj

### Input

The first line of the input contains an integer T denoting the number of test cases. The description of T test cases follows.The first line of each test case contains a single integer n denoting the number of numbers Alexandra has. The second line contains n space-separated distinct integers a1a2, …, an denoting these numbers.

### Output

For each test case, output a single line containing number of pairs for corresponding test case.

### Constraints

• 1 ≤ T ≤ 4
• 1 ≤ n ≤ 100000
• 0 ≤ ai ≤ 109
• All the ai are distinct

### Sample Input 1

``````2
2
2 1
3
3 1 2``````

### Sample Output 1

``````1
3
``````

### Explanation

Case 1: Only one such pair: (2,1)

Case 2: 3 possible pairs: (2,1), (2,3), (3,1)

### Magic Pairs CodeChef Solution in JAVA

```import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int T = sc.nextInt();
for (int tc = 0; tc < T; tc++) {
int n = sc.nextInt();
int[] a = new int[n];
for (int i = 0; i < a.length; i++) {
a[i] = sc.nextInt();
}
System.out.println(solve(a));
}
sc.close();
}
static long solve(int[] a) {
return (long) a.length * (a.length - 1) / 2;
}
}```

Disclaimer: The above Problem (Magic Pairs) is generated by CodeChef but the solution is provided by Chase2learn.This tutorial is only for Educational and Learning purpose.

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