Home » C programs » C string programs

C program to find the highest frequency of a character in the given string

Here, we are going to learn how to find the highest frequency of a character in the given string in C programming language?
Submitted by Nidhi, on July 20, 2021

Problem Solution:

Read a string from the user and find the highest frequency of a character in the given string using C program.

Program:

The source code to find the highest frequency of a character in the given string is given below. The given program is compiled and executed using GCC compile on UBUNTU 18.04 OS successfully.

// C program to find the highest frequency of a character
// in the given string

#include <stdio.h>
#include <string.h>

void printHighestFrequency(char* str)
{
    int i = 0;
    int j = 0;
    int k = 0;

    int len = 0;
    int high = 0;
    int index = 0;
    int flag = 0;

    char str1[64];
    int cnt[64] = { 0 };

    len = strlen(str);

    while (i < len) {
        if (i == 0) {
            str1[j++] = str[i];
            cnt[j - 1]++; // = cnt[j - 1] + 1;
        }
        else {
            for (k = 0; k < j; k++) {
                if (str[i] == str1[k]) {
                    cnt[k]++;
                    flag = 1;
                }
            }

            if (flag == 0) {
                str1[j++] = str[i];
                cnt[j - 1]++;
            }
            flag = 0;
        }
        i++;
    }

    for (i = 0; i < j; i++) {
        if ((i == 0) && (str1[i] != ' ')) {
            high = cnt[i];
            continue;
        }

        if ((high < cnt[i]) && (str1[i] != ' ')) {
            high = cnt[i];
            index = i;
        }
    }
    printf("Character '%c' is repeted %d time\n", str1[index], cnt[index]);
}

int main()
{
    char str[64];
    printf("Enter the string: ");
    scanf(" %[^\n]s", str);

    printHighestFrequency(str);

    return 0;
}

Output:

RUN 1:
Enter the string: this is india.
Character 'i' is repeted 4 time

RUN 2:
Enter the string: is are am
Character 'a' is repeted 2 time

RUN 3:
Enter the string: Hello world, how are you?
Character 'o' is repeted 4 time

Explanation:

In the above program, we created two functions printHighestFrequency() and main(). The printHighestFrequency() function is used to find the highest frequency character in string.

In the main() function, we read a string from the user and called the printHighestFrequency() function and printed the highest frequency character in the string on the console screen.

C String Programs »

---