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

int intIncrease(const void *i, const void *j) {
    // Must take const void * as arguments, so cast back to usable type
    int i1 = *((const int *) i);
    int i2 = *((const int *) j);
    // Positive if i > j, 0 if same, negative otherwise
    return i1 - i2;
}

int main() {
    int arr[10] = {1,4,7,2,9,3,0,8,5,6};
    qsort(arr, 10, sizeof(int), intIncrease);
    for(int i = 0; i < 10; i++)
        printf("%d ", arr[i]);
    printf("\n");
    return 0;
}