void makeheap(int s[], int n){
int i=(n-1)/2;
if(i>=0){
for(;i!=0;i--){
fixdown(s,i,n);
}
}
}
item_t pq_delmax(T t)
{
/* remenber to change the a[1] instead of a[0],
* because the the first element is inserted in position 1
* instead of position 0*/
swap(&t->content[1], t->content + t->size);
fixdown(t->content, 1, t->size - 1);
return t->content[t->size--];
}
void vheapsort(int s[], int n)
{
int i=n-1;
int temp;
makeheap(s, n);
for(;i>=1;i++){
temp=s[i];
s[i]=s[0];
s[0]=s[i];
fixdown(s,--n,0);
}
}