C Program to Count Number of Unique Words in a String

This C program counts the number of unique words in a given string. It tokenizes the input string, converts it to lowercase for case-insensitive comparison, and keeps track of unique words encountered.

Problem statement

Given a string, we need to find and count the number of unique words in it. The comparison should be case-insensitive, meaning that words with the same characters but different cases are considered the same (e.g., “hello” and “Hello” are treated as the same word).

C Program to Count Number of Unique Words in a String

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

#define MAX_WORDS 100
#define MAX_LENGTH 100

int countUniqueWords(char string[]);

int main() {
    // Introduction
    printf("C Program to Count Number of Unique Words in a String\n");

    // Problem statement
    printf("Problem Statement: Given a string, the program counts the number of unique words in the string.\n");

    // Rest of the program code...
}

How it works

This program counts the number of unique words in a string using the countUniqueWords function. It splits the string into words using strtok and stores each unique word in an array. The program then returns the count of unique words.

To compile and run the program, you can use a C compiler such as GCC. After running the program, you will be prompted to enter a string. Once you provide the input, the program will output the number of unique words in the string.

Input / output