C Heap Sort

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define MAX 10
#define SWAP(x,y) {int t; t = x; x = y; y = t;}

void createheap(int[]);
void heapsort(int[]);

int main(void) {
    int number[MAX+1] = {-1};
    int i, num; 

    srand(time(NULL));

    printf("排序前：");
    for(i = 1; i <= MAX; i++) {
        number[i] = rand() % 100;
        printf("%d ", number[i]);
    }

    printf("\n建立堆積樹：");
    createheap(number);
    for(i = 1; i <= MAX; i++)
        printf("%d ", number[i]);
    printf("\n");

    heapsort(number);

    printf("\n");

    return 0;
}

void createheap(int number[]) {
    int i, s, p;
    int heap[MAX+1] = {-1};

    for(i = 1; i <= MAX; i++) {
        heap[i] = number[i];
        s = i;
        p = i / 2;
        while(s >= 2 && heap[p] > heap[s]) {
            SWAP(heap[p], heap[s]);
            s = p;
            p = s / 2;
        }
    }

    for(i = 1; i <= MAX; i++)
        number[i] = heap[i];
   
}

void heapsort(int number[]) {
    int i, m, p, s;

    m = MAX;
    while(m > 1) {
        SWAP(number[1], number[m]);
        m--;

        p = 1;
        s = 2 * p;

        while(s <= m) {
if(s < m && number[s+1] < number[s])
                s++;
            if(number[p] <= number[s])
                break;
            SWAP(number[p], number[s]);
            p = s;
            s = 2 * p;
        }

        printf("\n排序中：");
        for(i = MAX; i > 0; i--)
            printf("%d ", number[i]);
    }
}