Minimum Swaps required to group all 1’s together
##### Submissions: 1580   Accuracy: 25.22%   Difficulty: Easy   Marks: 2

Given an array of 0’s and 1’s, we need to write a program to find the minimum number of swaps required to group all 1’s present in the array together.

Input:
The first line consists of a single integer T, the number of test cases. For each test case, the first line contains an integer denoting the size of the array followed by
n space separated integers.

Output:
For each test case, the output is an integer displaying the minimum number of swaps required and if no 1's are present print -1.

Constraints:
1<=T<=100
1<=n<=50

Example:
Input
2
5
1 0 1 0 1
6
1 0 1 0 1 1
Output
1
1

Explanation:
1. Only 1 swap is required to group all 1's together. Swapping index 1 and 4 will give arr[] = {1, 1, 1, 0, 0}.
2. Only 1 swap is required. Swapping index 0 and 3 will give arr[]={0, 0, 1, 1, 1, 1}.

#### ** For More Input/Output Examples Use 'Expected Output' option **

Contributor: Vanshika
Author: Vanshika_pec

If you have purchased any course from GeeksforGeeks then please ask your doubt on course discussion forum. You will get quick replies from GFG Moderators there.