我的c\c++之旅（三）——堆排序

堆排序

#define LEFT(i)     (2 * (i) + 1)

void Max_Heapify(int *sequence, int n, int i)
{
int child, tmp;

for(tmp = sequence[i]; LEFT(i) < n; i = child) {
child = LEFT(i);
if(child != n-1 && sequence[child+1] > sequence[child])
child++;
if(tmp < sequence[child])
sequence[i] = sequence[child];
else
break;
}
sequence[i] = tmp;
}

void Build_Max_Heap(int *sequence, int n)
{
int i;
for(i = n/2; i >= 0; i--)
Max_Heapify(sequence, n, i);
}

void Heap_Sort(int *sequence, int n)
{
int i;

Build_Max_Heap(sequence, n);
for(i = n-1; i > 0; i--) {
int tmp = sequence[0];
sequence[0] = sequence[i];
sequence[i] = tmp;
Max_Heapify(sequence, i, 0);
}
}