C++ Exercises: Separate 0s and 1s from a given array of values 0 and 1

Last update on August 16 2025 12:55:25 (UTC/GMT +8 hours)

14. Separate 0s and 1s from an Array

Write a C++ program to separate 0s and 1s from a given array of values 0 and 1.

Visual Presentation:

C++ Exercises: Separate 0s and 1s from a given array of values 0 and 1

Sample Solution:

C++ Code :

#include<iostream> // Header file for input/output stream
using namespace std; // Using the standard namespace

// Function to segregate 0s and 1s in the array
void segregateEvenOdd(int nums[], int n)
{
    int ctr = 0; // Initialize a counter for the number of zeroes

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

    // Place the counted zeroes at the beginning of the array
    for (int i = 0; i < ctr; i++)
        nums[i] = 0;

    // Place the remaining ones after the zeroes in the array
    for (int i = ctr; i < n; i++)
        nums[i] = 1;
}

// Main function
int main()
{
    int nums[] = {0, 1, 0, 0 , 1, 1, 1, 0, 1, 0}; // Declaration and initialization of an integer array
    int n = sizeof(nums)/sizeof(nums[0]); // Calculate the number of elements in the array
    cout << "Original array: ";
    for (int i=0; i < n; i++) 
    cout << nums[i] <<" "; // Output each element of the original array
    segregateEvenOdd(nums, n); // Rearrange the array by segregating 0s and 1s
    cout << "\nArray after segregation: ";
    for (int i=0; i < n; i++) 
    cout << nums[i] <<" "; // Output each element of the modified array
    return 0;     
}

Sample Output:

Original array: 0 1 0 0 1 1 1 0 1 0 
Array after divided: 0 0 0 0 0 1 1 1 1 1

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program to rearrange an array containing only 0s and 1s so that all 0s appear before all 1s.
Write a C++ program that reads an array of binary values and partitions it into two sections, with 0s first.
Write a C++ program to sort an array of 0s and 1s using a two-pointer approach without extra space.
Write a C++ program that uses counting sort to rearrange an array consisting of only 0s and 1s.

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