pvjc24/cv10/program.c

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

int compare_strings(const void *a, const void *b) {
    const char *str1 = *(const char **)a;
    const char *str2 = *(const char **)b;
    return strcmp(str1, str2);
}

int main() {
    int max_students, read;
    char buffer[101];
    char **names = NULL;
    size_t count = 0;
    size_t capacity = 0;


    if (scanf("%d", &max_students) != 1 || max_students <= 0) {
        puts("Nespravny vstup");
        return 1;
    }


    while (fgets(buffer, sizeof(buffer), stdin)) {

        buffer[strcspn(buffer, "\n")] = 0;
        if (strlen(buffer) == 0) break; 


        if (count == capacity) {
            capacity = capacity == 0 ? 16 : capacity * 2;
            char **new_names = realloc(names, capacity * sizeof(char *));
            if (!new_names) {
                puts("Memory allocation failed");
                free(names);
                return 1;
            }
            names = new_names;
        }


        names[count] = strdup(buffer);
        if (!names[count]) {
            puts("Memory allocation failed");
            while (count > 0) free(names[--count]);
            free(names);
            return 1;
        }
        count++;
    }

    if (count == 0) {
        puts("Ziadne prihlasky");
        free(names);
        return 1;
    }


    qsort(names, count, sizeof(char *), compare_strings);


    size_t unique_count = 0;
    for (size_t i = 0; i < count; i++) {
        if (unique_count == 0 || strcmp(names[unique_count - 1], names[i]) != 0) {
            names[unique_count++] = names[i];
        } else {
            free(names[i]);
        }
    }


    puts("Prijati studenti:");
    size_t limit = max_students < unique_count ? max_students : unique_count;
    for (size_t i = 0; i < limit; i++) {
        puts(names[i]);
    }


    if (limit < unique_count) {
        puts("Neprijati studenti:");
        for (size_t i = limit; i < unique_count; i++) {
            puts(names[i]);
            free(names[i]);
        }
    }


    for (size_t i = 0; i < limit; i++) {
        free(names[i]);
    }
    

    free(names);
    return 0;
}