C Exercises: Segregate 0s and 1s in an array

Last update on March 18 2025 13:23:14 (UTC/GMT +8 hours)

95. Segregate 0s and 1s in Array

Write a program in C to segregate 0s and 1s in an array.

Expected Output:
The given array is:
1 0 1 0 0 1 0 1 1<>br> The array after segregation is: 0 0 0 0 1 1 1 1 1

The task is to write a C program that segregates 0s and 1s in a given array such that all 0s are moved to the beginning and all 1s to the end of the array. The program should traverse the array, rearrange the elements accordingly, and then display the modified array with all 0s followed by all 1s.

Sample Solution:

C Code:

#include <stdio.h>

// Function to segregate 0s and 1s in an array
void segZeroAndOne(int arr1[], int n) 
{ 
    int ctr = 0; // Counter to keep track of 0s

    // Count the number of 0s in the array
    for (int i = 0; i < n; i++) { 
        if (arr1[i] == 0) 
            ctr++; 
    } 

    // Assign 0s to the first 'ctr' elements of the array
    for (int i = 0; i < ctr; i++) 
        arr1[i] = 0; 

    // Assign 1s to the remaining elements of the array
    for (int i = ctr; i < n; i++) 
        arr1[i] = 1; 
} 

// Function to print the segregated array
void printSegre(int arr1[], int n) 
{ 
    printf("The array after segregation is: "); 
    for (int i = 0; i < n; i++) 
        printf("%d  ", arr1[i]); 
} 

int main() 
{ 
    // Given input array
    int arr1[] = { 1, 0, 1, 0, 0, 1, 0, 1, 1 }; 
    int n = sizeof(arr1) / sizeof(arr1[0]); 
	int i;

    //------------- print original array ------------------	
	printf("The given array is:  \n");
	for(i = 0; i < n; i++)
	{
		printf("%d  ", arr1[i]); // Print the original array
	}
	printf("\n");
//-----------------------------------------------------------

    // Segregate 0s and 1s in the array
    segZeroAndOne(arr1, n); 
    // Print the segregated array
    printSegre(arr1, n); 

    return 0; 
}

Output:

The given array is:  
1  0  1  0  0  1  0  1  1  
The array after segregation is: 0  0  0  0  1  1  1  1  1

Visual Presentation:

Flowchart:/p>

For more Practice: Solve these Related Problems:

• Write a C program to segregate 0s and 1s in an array using two-pointer technique without extra space.
• Write a C program to count the number of 0s and 1s and then reconstruct the sorted array.
• Write a C program to segregate 0s and 1s and then verify by printing the frequency of each.
• Write a C program to segregate binary elements and then swap the first and last halves of the array.

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