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

#define MAX_NAME_LENGTH 100

int compare(const void *a, const void *b) {
    return strcmp(*(const char **)a, *(const char **)b);
}

void free_memory(char **array, int length) {
    for (int i = 0; i < length; i++) {
        free(array[i]);
    }
    free(array);
}

int main() {
    int max_students;
    char name[MAX_NAME_LENGTH];
    char **students = NULL;
    int num_students = 0;
    
    printf("Enter the maximum number of students that can be accepted: ");
    if (scanf("%d\n", &max_students) != 1 || max_students <= 0) {
        puts("Invalid input for the number of students.");
        return 1;
    }

    students = (char **)malloc(max_students * sizeof(char *));
    if (students == NULL) {
        puts("Memory allocation failed.");
        return 1;
    }

    printf("Enter student names (press Enter twice to stop):\n");
    while (fgets(name, MAX_NAME_LENGTH, stdin)) {
        if (name[strcspn(name, "\n")] = '\0', !*name) 
            break;

        int is_duplicate = 0;
        for (int i = 0; i < num_students; i++) {
            if (strcmp(students[i], name) == 0) {
                is_duplicate = 1;
                break;
            }
        }

        if (!is_duplicate) {
            if (num_students < max_students) {
                students[num_students] = strdup(name);
                if (students[num_students] == NULL) {
                    puts("Memory allocation failed.");
                    free_memory(students, num_students);
                    return 1;
                }
                num_students++;
            }
        }
    }

    if (num_students == 0) {
        puts("No applications were received.");
        free(students);
        return 1;
    }

    qsort(students, num_students, sizeof(char *), compare);

    puts("Accepted students:");
    for (int i = 0; i < num_students; i++) {
        puts(students[i]);
    }

    free_memory(students, num_students);

    return 0;
}