Sorting Array of Strings

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    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    int lexicographic_sort(const char* a, const char* b) {
        return strcmp(a, b);
    
    }
    
    int lexicographic_sort_reverse(const char* a, const char* b) {
        return strcmp(b, a);
    
    }
    
    int sort_by_number_of_distinct_characters(const char* a, const char* b) {
        int count_a = 0, count_b = 0;
        int char_count[26] = {0};
    
        for (const char* p = a; *p; p++) {
            if (!char_count[*p - 'a']) {
                char_count[*p - 'a'] = 1;
                count_a++;
            }
        }
    
        memset(char_count, 0, sizeof(char_count));
    
        for (const char* p = b; *p; p++) {
            if (!char_count[*p - 'a']) {
                char_count[*p - 'a'] = 1;
                count_b++;
            }
        }
    
        if (count_a == count_b) {
            return strcmp(a, b);
        } else {
            return count_a - count_b;
        }
        
    }
    
    int sort_by_length(const char* a, const char* b) {
        int len_a = strlen(a);
        int len_b = strlen(b);
    
        if (len_a == len_b) {
            return strcmp(a, b);
        } else {
            return len_a - len_b;
        }
        
    }
    
    void string_sort(char** arr,const int len,int (*cmp_func)(const char* a, const char* b)){
                for (int i = 0; i < len - 1; i++) {
            for (int j = i + 1; j < len; j++) {
                if (cmp_func(arr[i], arr[j]) > 0) {
                    char* temp = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                }
            }
        }
    }
    
    
    int main() 
    {
        int n;
        scanf("%d", &n);
      
        char** arr;
    	arr = (char**)malloc(n * sizeof(char*));
      
        for(int i = 0; i < n; i++){
            *(arr + i) = malloc(1024 * sizeof(char));
            scanf("%s", *(arr + i));
            *(arr + i) = realloc(*(arr + i), strlen(*(arr + i)) + 1);
        }
      
        string_sort(arr, n, lexicographic_sort);
        for(int i = 0; i < n; i++)
            printf("%s\n", arr[i]);
        printf("\n");
    
        string_sort(arr, n, lexicographic_sort_reverse);
        for(int i = 0; i < n; i++)
            printf("%s\n", arr[i]); 
        printf("\n");
    
        string_sort(arr, n, sort_by_length);
        for(int i = 0; i < n; i++)
            printf("%s\n", arr[i]);    
        printf("\n");
    
        string_sort(arr, n, sort_by_number_of_distinct_characters);
        for(int i = 0; i < n; i++)
            printf("%s\n", arr[i]); 
        printf("\n");
    }