堆排序

void maxheapify(int *data,int i){
    int left = 2*i;
    int right = 2*i+1;
    int largest;
    if(data[i]<data[left])
        largest = left;
    else
        largest = i;
    if(data[right]>data[largest])
        largest = right;
    if(largest!=i){
        int temp = data[i];
        data[i] = data[largest];
        data[largest] = temp;
    }
    maxheapify(data,largest);
}
void initheap(int *data,int len){
    for(int i = len/2;i>0;--i)
        maxheapify(data,i);
}
void heapsort(int *data,int len){
    initheap(data,len);
    for(int i = len-1;i>1;--i){
        int temp = data[0];
        data[0] = data[i];
        data[i] = temp;
        maxheapify(data,0);
    }
}