Write a C program to count frequency of each element of an array.

 Source code:

/*Write a C program to count frequency of each element of an array. Frequency of a particular element will be printed once.*/

#include <stdio.h>

int main()

{

    int arr[50], freq[50]; /* Array arr[50] stores the elements and freq[50] stores the no. of times the element occurs */

    int size, i, j, count;

printf("Enter the size of array:");

    scanf("%d", &size);

    printf("Enter the values of the array :\n");

    for(i=0; i<size; i++)

    {

        scanf("%d", &arr[i]);

        freq[i] = -1; 

/* all frequencies are initialized to -1 which will be changed to specific value after counting no. of occurrence */

/* for the element which is already counted the corresponding frequency will be made 0 */ 

    }

for(i=0; i<size; i++)

    {

        count = 1;

        for(j=i+1; j<size; j++)

        {

            /* If duplicate element is found */

            if(arr[i]==arr[j])

            {

                count++;

                /* Make sure not to count frequency of same element again */

                freq[j] = 0;

            }

        }

        /* If frequency of current element is not counted */

        if(freq[i] != 0)

        {

            freq[i] = count;

        }

    }

   /* Print frequency of each element */

    for(i=0; i<size; i++)

    {

        if(freq[i] != 0) /* The element with corresponding frequency 0 means duplicate occurrence of the element */

        {

            printf("%d occurs %d times\n", arr[i], freq[i]);

        }

    }

return 0;

}

Output: