C Exercises: Find the majority element of an array

Last update on January 17 2025 13:19:10 (UTC/GMT +8 hours)

Write a program in C to find the majority element of an array.
A majority element in an array A[] of size n is an element that appears more than n/2 times (and hence there is at most one such element).

The task requires writing a C program to identify the majority element in an array, which is defined as an element that appears more than half the time in the array. The program should count occurrences of each element and determine if any element meets this criterion, then output the result.

Visual Presentation:

C Exercises: Find the majority element of an array

Sample Solution:

C Code:

#include <stdio.h>

// Function to find the majority element in an array
void findMajElem(int *arr1, int n) {
    int i, IndexOfMajElem = 0, ctr = 1;

    // Finding the candidate for the majority element
    for (i = 1; i < n; i++) {
        if (arr1[IndexOfMajElem] == arr1[i])
            ctr++;
        else
            ctr--;

        if (ctr == 0) {
            IndexOfMajElem = i;
            ctr = 1;
        }
    }

    ctr = 0;
    // Count occurrences of the candidate to confirm it as a majority element
    for (i = 0; i < n; i++) {
        if (arr1[i] == arr1[IndexOfMajElem])
            ctr++; 
    }

    // Checking if the candidate element occurs more than n/2 times
    if (ctr > (n / 2))
        printf("Majority Element : %d\n", arr1[IndexOfMajElem]);
    else
        printf("There are no Majority Elements in the given array.\n");
}

// Main function
int main() {
    int i, ctr;
    int arr1[] = { 4, 8, 4, 6, 7, 4, 4, 8 };
    ctr = sizeof(arr1) / sizeof(arr1[0]);

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

    // Function call to find the majority element
    findMajElem(arr1, ctr);

    return 0;
}

Sample Output:

The given array is :  4  8  4  6  7  4  4  8  
There are no Majority Elements in the given array.

Flowchart :

C Programming Code Editor:

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