C Exercises: Sort an array of 0s, 1s and 2s

C Array: Exercise-54 with Solution

Write a program in C to sort an array of 0s, 1s and 2s.

Pictorial Presentation:

Sample Solution:

C Code:

#include <stdio.h>
void changePlace(int arr1[], int i, int j) 
{
    int tmp = arr1[i];
    arr1[i] = arr1[j];
    arr1[j] = tmp;
}
int sortElements(int arr1[], int end)
{
    int start = 0, mid = 0;
    int pivot = 1;
    while (mid <= end)
    {
        if (arr1[mid] < pivot) 
        {
            changePlace(arr1, start, mid);
            ++start, ++mid;
        }
        else if (arr1[mid] > pivot) 
        {
            changePlace(arr1, mid, end);
            --end;
        }
        else                        
        {
            ++mid;
        }
    }
}

int main()
{
    int arr1[] = { 0, 1, 2, 2, 1, 0, 0, 2, 0, 1, 1, 0 };
    int n = sizeof(arr1)/sizeof(arr1[0]);
	int i;
 //------------- print original array ------------------	
	printf("The given array is :  ");
	for(i = 0; i < n; i++)
	{
	printf("%d  ", arr1[i]);
    } 
	printf("\n");
//------------------------------------------------------ 	
	printf("After sortig the elements in the array are: \n");
    sortElements(arr1, n - 1);
    for (int i = 0 ; i < n; i++) 
	{
        printf("%d ", arr1[i]);
    }
    return 0;
}

Sample Output:

The given array is :  0  1  2  2  1  0  0  2  0  1  1  0  
After sortig the elements in the array are: 
0 0 0 0 0 1 1 1 1 2 2 2 

Flowchart:

C Programming Code Editor:

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