C Exercises: Find the two repeating elements in a given array

Last update on March 18 2025 13:21:21 (UTC/GMT +8 hours)

44. Find Two Repeating Elements

Write a program in C to find the two repeating elements in a given array.

Visual Presentation:

Sample Solution:

C Code:

#include<stdio.h>
#include<stdlib.h>

// Function to find and display the elements that are repeated in the array
void find2RepetElement(int arr1[], int arr_size) {
    int i, j;
    printf("The repeating elements are: ");
    for(i = 0; i < arr_size; i++) {
        for(j = i + 1; j < arr_size; j++) {
            if(arr1[i] == arr1[j]) {
                printf(" %d ", arr1[i]);
            }
        }
    }
}

int main() {
    int arr1[] = {2, 7, 4, 7, 8, 3, 4};
    int ctr = sizeof(arr1) / sizeof(arr1[0]);
    int i;

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

    // Find and display the repeating elements in the array
    find2RepetElement(arr1, ctr);
    return 0;
}

Sample Output:

The given array is :  2  7  4  7  8  3  4  
The repeating elements are:  7  4

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C program to find the two repeating elements in an array using sorting and then comparing adjacent elements.
• Write a C program to identify the two duplicates in an array using a hash table.
• Write a C program to find two repeating numbers in an array without using extra space.
• Write a C program to detect two duplicate elements using bitwise XOR operations.

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