Segregate 0s and 1s in an array

Segregate 0s and 1s in an array

// C program to sort a binary array in one pass

#include<stdio.h>

/*Function to put all 0s on left and all 1s on right*/

void segregate0and1(int arr[], int size)

{

    /* Initialize left and right indexes */

    int left = 0, right = size-1;

    while (left < right)

    {

        /* Increment left index while we see 0 at left */

        while (arr[left] == 0 && left < right)

            left++;

        /* Decrement right index while we see 1 at right */

        while (arr[right] == 1 && left < right)

            right--;

        /* If left is smaller than right then there is a 1 at left

          and a 0 at right.  Exchange arr[left] and arr[right]*/

        if (left < right)

        {

            arr[left] = 0;

            arr[right] = 1;

            left++;

            right--;

        }

    }

}

 /* driver program to test */

int main()

{

    int arr[] = {0, 1, 0, 1, 1, 1};

    int i, arr_size = sizeof(arr)/sizeof(arr[0]);

 segregate0and1(arr, arr_size);

    printf("Array after segregation ");

    for (i = 0; i < 6; i++)

        printf("%d ", arr[i]);

    getchar();

    return 0;

}

Output:

Array after segregation is 0 0 1 1 1 1

Example:

Input array   =  [0, 1, 0, 1, 0, 0, 1, 1, 1, 0]

Output array =  [0, 0, 0, 0, 0, 1, 1, 1, 1, 1]