C++ Exercises: Move all negative elements of an array of integers to the end of the array without changing the order of positive element and negative element

Last update on April 12 2025 12:56:05 (UTC/GMT +8 hours)

18. Move Negative Elements to the End

Write a C++ program to move all negative elements of an array of integers to the end of the array. This is done without changing the order of the positive and negative elements of the array.

Sample Solution:

C++ Code :

#include <iostream> // Header file for input/output stream
#include <cstring>   // Header file for C-style string operations
using namespace std; // Using the standard namespace

// Function to segregate positive and negative elements in an array
void segregateElements(int nums[], int n)
{
    int result[n]; // Array to store the segregated elements

    int j = 0; // Index to track positive elements in the result array
    for (int i = 0; i < n; i++) {
        if (nums[i] >= 0)
            result[j++] = nums[i]; // Store positive elements at the beginning of 'result'
    }

    // If all elements are positive or all elements are negative, return without further processing
    if (j == n || j == 0)
        return;

    for (int i = 0; i < n; i++) {
        if (nums[i] < 0)
            result[j++] = nums[i]; // Store negative elements after positive elements in 'result'
    }

    // Copy the contents of 'result' back to 'nums'
    memcpy(nums, result, sizeof(result));
}

// Main function
int main()
{
    int nums[] = {0, 9, -7, 2, -12, 11, -20}; // 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
    segregateElements(nums, n); // Segregate positive and negative elements in the array
    cout << "\nArray elements after rearrange: ";
    for (int i = 0; i < n; i++)
        cout << nums[i] << " "; // Output each element of the modified array after rearrangement
    return 0;
}

Sample Output:

Original array: 0 9 -7 2 -12 11 -20 
Array elements after rearrange: 0 9 2 11 -7 -12 -20

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program to move all negative numbers in an array to the end while preserving the order of positive numbers.
Write a C++ program that reads an array and reorders it so that all negatives appear at the end using a two-pass algorithm.
Write a C++ program to partition an array into positive and negative elements without disturbing their original order.
Write a C++ program that creates a new array where all non-negative numbers are listed first, followed by negative numbers, maintaining their sequence.

C++ Code Editor:

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