/*
 * Program to test/demo sorting using "random" data.
 *
 * Requires two command-line arguments, count and seed.
 *
 * Incomplete -- doesn't actually sort data yet.
 */
#include <stdio.h>
#include <stdlib.h>

void sort(int sz, int data[]);

int main(int argc, char *argv[]) {
    if (argc < 3) {
        puts("requires two command-line arguments, count and seed");
        return 1;
    }
    char *endptr;
    long count = strtol(argv[1], &endptr, 10);
    if ((*endptr != '\0') || (count <= 0)) {
        puts("count must be positive integer");
        return 1;
    }
    long seed = strtol(argv[2], &endptr, 10);
    if ((*endptr != '\0') || (count <= 0)) {
        puts("seed must be positive integer");
        return 1;
    }

    int * data = malloc(sizeof(data[0]) * count);
    if (data == NULL) {
        printf("cannot allocate array of size %ld\n", count);
        return 1;
    }

    /* fill array with "random" values */
    srand(seed);
    for (int i = 0; i < count; ++i) {
        data[i] = rand();
    }

    /* sort array */
    sort(count, data);
    /* FIXME */

    /* print result */
    for (int i = 0; i < count; ++i) {
        printf("element %d is %d\n", i, data[i]);
    }

    /* check "is it sorted" */
    puts("");
    for (int i = 0; i < count-1; ++i) {
        if (data[i] > data[i+1]) {
            printf("element %d out of order\n", i+1);
        }
    }

    free(data);
    return 0;
}

int compare(const void *e1, const void *e2) {
	int *i1 = (int *) e1;
	int *i2 = (int *) e2;
	if (*i1 < *i2) 
		return -1;
	else if (*i1 > *i2)
		return 1;
	else
		return 0;
}

void sort(int sz, int data[]) {
	qsort(data, sz, sizeof data[0], compare);
}