#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define num 5
struct library{
    char author[10];
    char name[10];
    int age;
};

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

int main() {

    struct library arr[num];
    strcpy(arr[0].author, "Danik");
    strcpy(arr[1].author, "Ivan");
    strcpy(arr[2].author, "Alexander");
    strcpy(arr[3].author, "Andrew");
    strcpy(arr[4].author, "Vlad");
    strcpy(arr[0].name, "Story");
    strcpy(arr[1].name, "Aktios");
    strcpy(arr[2].name, "KPO");
    strcpy(arr[3].name, "Red hat1");
    strcpy(arr[4].name, "Matvei");
    arr[0].age = 2000;
    arr[1].age = 1900;
    arr[2].age = 2010;
    arr[3].age = 2015;
    arr[4].age = 1999;
    for (size_t i = 0; i < num; ++i) {
        printf("%s", arr[i].author);
        printf("%s", " - ");
        printf("%s", arr[i].name);
        printf("%s", " - ");
        printf("%d\n", arr[i].age);
    }
    struct library *strings[4];
    int k = 0;
    for (int i = 0; i < num; i++){
        if (arr[i].age > 2000){
            strings[k] = &arr[i];
            k++;
        }
    }
    qsort(strings, k, sizeof(strings[0]), compareStrings);
    puts ("\n");
    printf("Sorted array:\n");
    for (size_t i = 0; i < k; ++i) {
        printf("%s", strings[i]->author);
        printf("%s", " - ");
        printf("%s", strings[i]->name);
        printf("%s", " - ");
        printf("%d\n", strings[i]->age);
    }
    return 0;
}