HDU 1425 sort

堆排序

题目链接http://acm.hdu.edu.cn/showproblem.php?pid=1425

关于堆排序讲解详看http://www.cnblogs.com/dolphin0520/archive/2011/10/06/2199741.html

代码跑了562MS 实在是仰慕用93MS跑出来的

这个题还必须用C交 用GCC交会TLE

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define  N 1000005
int a[N];
void heapadjust(int *a,int i,int n)
{
    int lchild=2*i,rchild=2*i+1;
    int max=i,t;
    if(i<=n/2)
    {
        if(lchild<=n&&a[lchild]>a[max])
    {
        max=lchild;
    }
    if(rchild<=n&&a[rchild]>a[max])
    {
        max=rchild;
    }
    if(max!=i)
    {
        t=a[i];a[i]=a[max];a[max]=t;
        heapadjust(a,max,n);
    }
    }
}
void heapbuild(int *a,int n)
{
    int i;
    for(i=n/2;i>=1;i--)
    {
        heapadjust(a,i,n);
    }
}
void heapsort(int *a,int n)
{
    int i,t;
    heapbuild(a,n);
    for(i=n;i>=1;i--)
    {
        t=a[1];a[1]=a[i];a[i]=t;
        heapadjust(a,1,i-1);
    }
}
int main()
{
    int i,n,m;
    while(scanf("%d %d",&n,&m)!=EOF)
    {
        for( i=1;i<=n;i++)
    {
        scanf("%d",&a[i]);
    }
    heapsort(a,n);
    for(i=n;i>n-m+1;i--)
    {
        printf("%d ",a[i]);
    }
    printf("%d",a[n-m+1]);
    puts("");
    }
    return 0;
}