Example: Find First Non-Repeating Character (Brute-Force) in C

// Find First Non-Repeating Character (Brute-Force)
#include <stdio.h>
#include <string.h> // For strlen

int main() {
    char str[] = "programming"; // Example string
    int len = strlen(str);
    char firstNonRepeating = '\0'; // Initialize with null character

    // Step 1: Iterate through each character of the string
    for (int i = 0; i < len; i++) {
        int count = 0; // Reset count for current character
        
        // Step 2: For each character, iterate through the string again to count occurrences
        for (int j = 0; j < len; j++) {
            if (str[i] == str[j]) {
                count++;
            }
        }
        
        // Step 3: If a character appears exactly once, it's a non-repeating character
        if (count == 1) {
            firstNonRepeating = str[i]; // Store it as the first found
            break; // Since we need the *first* one, we can stop
        }
    }

    // Step 4: Print the result
    if (firstNonRepeating != '\0') {
        printf("The first non-repeating character is: %c\n", firstNonRepeating);
    } else {
        printf("No non-repeating character found.\n");
    }

    return 0;
}