C++ Exercises: Find the element that appears once in an array of integers and every other element appears twice

Last update on December 20 2024 12:20:18 (UTC/GMT +8 hours)

Write a C++ program to find the element that appears once in an array of integers and every other element appears twice.

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Sample Solution:

C++ Code :

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

// Function to find the single element in an array with duplicate elements
int search_single_element(int array1[], int s1)
{
    int result = array1[0]; // Initialize the result with the first element of the array

    // Iterate through the array starting from the second element
    for (int i = 1; i < s1; i++)
        result = result ^ array1[i]; // Perform bitwise XOR operation to find the single element

    return result; // Return the single element found
}

// Main function
int main()
{
    int array1[] = {3, 1, 5, 1, 5, 7, 9, 7, 9}; // Declaration and initialization of the array
    int se; // Variable to store the single element

    int s1 = sizeof(array1) / sizeof(array1[0]); // Calculate the size of the array

    cout << "Original array: "; // Output label for the original array

    // Output each element of the original array
    for (int i = 0; i < s1; i++)
        cout << array1[i] << " ";

    se = search_single_element(array1, s1); // Call the function to find the single element
    cout << "\nSingle element: " << se; // Output the single element
    return 0; // Return 0 to indicate successful execution
}

Sample Output:

Original array: 3 1 5 1 5 7 9 7 9 
Single element: 3

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