C Program to Count Frequency of Each Element in an Array

Write a C program to count the frequency of each element in an array. This C program accepts an array from the user and find out the count of each element in the array.

C Program:

/* C program to count frequency of each element of array */

#include <stdio.h>

int main()
{
    int arr[100], freq[100];
    int size, i, j, count;

    printf("Enter size of array: ");
    scanf("%d", &size);

    printf("Enter elements in array: ");
    for(i=0; i<size; i++)
    {
        scanf("%d", &arr[i]);

        freq[i] = -1;
    }


    for(i=0; i<size; i++)
    {
        count = 1;
        for(j=i+1; j<size; j++)
        {
            if(arr[i]==arr[j])
            {
                count++;

                freq[j] = 0;
            }
        }

        if(freq[i] != 0)
        {
            freq[i] = count;
        }
    }

    printf("\nFrequency of all elements of array : \n");
    for(i=0; i<size; i++)
    {
        if(freq[i] != 0)
        {
            printf("%d occurs %d times\n", arr[i], freq[i]);
        }
    }

    return 0;

}

Example Output:

Input array elements: 5, 10, 2, 5, 50, 5, 10, 1, 2, 2

Frequency of 5 = 3
Frequency of 10 = 2
Frequency of 2 = 3
Frequency of 50 = 1
Frequency of 1 = 1