堆排序练习 hdu 1425 sort

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

int a[1000002];

void heapadjust(int *a, int k, int n)
{
int i, j;
i=k;
j=2*i;
a[0]=a[i];
while(j<=n)
{
if ((j<n) && a[j]>a[j+1])
j++;
if (a[0]>a[j])
{
a[i]=a[j];
i=j;
j=2*i;
}
else
break;
}
a[i]=a[0];
}

void heapsort(int *a, int n)
{
int j;
for (j=n/2; j>=1; j--)
heapadjust(a, j, n);
for (j=n; j>1; j--)
{
a[0]=a[j];
a[j]=a[1];
a[1]=a[0];
heapadjust(a, 1, j-1);
}
}

int main()
{
int n, m, i;
while(scanf("%d%d", &n, &m)==2)
{
for (i=1; i<=n; i++)
scanf("%d", &a[i]);
heapsort(a, n);
if (m>n)
m=n;
for (i=1; i<=m; i++)
{
printf("%d", a[i]);
if (i==m)
printf("\n");
else
printf(" ");
}
}
}