Example: Anagram Check (Sorting Method) in C

// Anagram Check (Sorting Method)
#include <stdio.h>
#include <string.h>
#include <stdlib.h> // For qsort

// Comparison function for qsort
int compareChars(const void *a, const void *b) {
    return (*(char*)a - *(char*)b);
}

// Function to check if two strings are anagrams using sorting
int areAnagramsSorting(char *str1, char *str2) {
    // Step 1: Get lengths of both strings
    int len1 = strlen(str1);
    int len2 = strlen(str2);

    // Step 2: If lengths are different, they cannot be anagrams
    if (len1 != len2) {
        return 0; // Not anagrams
    }

    // Step 3: Create copies of the strings to avoid modifying originals
    char *s1_copy = (char *)malloc(sizeof(char) * (len1 + 1));
    char *s2_copy = (char *)malloc(sizeof(char) * (len2 + 1));
    if (s1_copy == NULL || s2_copy == NULL) {
        perror("Memory allocation failed");
        exit(EXIT_FAILURE);
    }
    strcpy(s1_copy, str1);
    strcpy(s2_copy, str2);

    // Step 4: Sort both copied strings
    qsort(s1_copy, len1, sizeof(char), compareChars);
    qsort(s2_copy, len2, sizeof(char), compareChars);

    // Step 5: Compare the sorted strings
    int result = strcmp(s1_copy, s2_copy) == 0;

    // Step 6: Free dynamically allocated memory
    free(s1_copy);
    free(s2_copy);

    return result;
}

int main() {
    char str1[] = "listen";
    char str2[] = "silent";
    char str3[] = "hello";
    char str4[] = "world";

    printf("Checking \"%s\" and \"%s\":\n", str1, str2);
    if (areAnagramsSorting(str1, str2)) {
        printf("They are anagrams.\n");
    } else {
        printf("They are not anagrams.\n");
    }

    printf("\nChecking \"%s\" and \"%s\":\n", str3, str4);
    if (areAnagramsSorting(str3, str4)) {
        printf("They are anagrams.\n");
    } else {
        printf("They are not anagrams.\n");
    }

    return 0;
}