线性建堆, 堆，堆排序,

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

#define swap(a, b) ({
                __typeof(a) c = a;
                a = b, b = c;
                })

int down_updata (int *p, int i, int n) {
        int temp = i;
        while ((i << 1) <= n) {
                p[i] < p[(i << 1)] && (temp = i << 1);
                (i << 1 | 1) <= n && p[(i << 1 | 1)] > p[temp] && (temp = (i << 1 | 1));
                if (temp == i) break;
                swap(p[i], p[temp]);
                i = temp;
        }
        return 0;
}

void output(int *p, int n) {
        for (int i = 0; i < n; i++) printf("%d, ", p[i]);
        printf("
");
        return ;
}

int heap_sort(int *p, int n) {
        p -= 1;
        for (int i = n >> 1; i > 0; i--) down_updata(p, i, n);
        for (int i = n; i > 1; i--) {
                swap(p[i], p[1]);
                down_updata(p, 1, i - 1);
        }
        return 1;
}

int main() {
        srand(time(0));
#define MAX_N 20
        int temp = 1, *ar = (int *)malloc(sizeof(int) * (MAX_N + 1));
        for (int i = 0; i < MAX_N; i++) ar[i] = rand() % 100;
        output(ar, MAX_N);
        heap_sort(ar, MAX_N);
        output(ar, MAX_N);
#undef MAX_N
        return 0;
}