堆排序实现

#include <stdio.h>
#include <time.h>
#define N 7

void swap(int a[], int m, int n)
{
    int tmp;
    tmp = a[m];
    a[m] = a[n];
    a[n] = tmp;
}

void headadjust(int a[], int i, int end)
{
    int dad;                                 //定义父节点，子节点
    int son;
    dad = i;
    son = 2 * dad + 1;

    while(son <end)                        
    {
        if(son + 1 < end && a[son] < a[son + 1])   
        {
            son++;
        }

        if(a[son] > a[dad])
        {
            swap(a, son, dad);
        }

        dad = son;
        son = 2 * dad + 1;
    }
}



void heapsort(int a[],int  len)
{
    int i, n;
    int end;

    end = len;


    for(i = end / 2.0 -1; i >= 0; i--)
    {
        headadjust(a, i, end);
    }


    end--;
    while(end > 0)
    {
        swap(a, 0, end);
        end--;
        headadjust(a, 0, end);
    }
}


int main()
{
    int i;
    int a[N];

    srand((unsigned)time(NULL));
    for(i = 0; i < N; i++)
    {
        a[i] = rand() % 100;
        printf("%d ", a[i]);
    }
    printf("\n");

    heapsort(a, N);

    for(i = 0; i < N; i++)
    {
        printf("%d ", a[i]);
    }

    printf("\n");
    return 0;
}