#include <inttypes.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>

typedef struct data {
    int (*get_rank)(const struct data*);
    int rank;
} data;

int get_rank(const data* d) {
    return (d->rank);
}

int strcmp(const void * x1, const void * x2)
{
    data* t1 = (data*)x1;
    data* t2 = (data*)x2;
    return (t1->get_rank(t1) - t2->get_rank(t2));
}

typedef int (*comparator_t)(const void *, const void *);

comparator_t comp = strcmp;

void rank_sort(data* elements[], size_t size) {
    qsort(elements, size, sizeof(data*), comp);
}

enum {
    syze = 3
};

int main() {
    data* a = malloc(sizeof(data));
    a->get_rank = get_rank;
    a->rank = 1;
    data* b = malloc(sizeof(data));
    b->get_rank = get_rank;
    b->rank = 2;
    data* c = malloc(sizeof(data));
    c->get_rank = get_rank;
    c->rank = 3;
    data* els[] = {c, a, b};
    for (int i = 0; i < syze; ++i) {
        printf("%d ", els[i]->get_rank(els[i]));
        fflush(stdout);
    }
    printf("\n");

    rank_sort(els, syze);

    // for (int i = 0; i < syze; ++i) {
    //     printf("%d ", els[i]->get_rank(els[i]));
    // }
    // printf("\n");
}