堆排序

　　

#include <iostream>
#define len(x) (unsigned int)sizeof(x)/sizeof(x[0])

using namespace std;

void Swap(int x[],int i,int j){
//    int tem = x[i];
//    x[i] = x[j];
//    x[j] = tem;
//
//    x[i]^=x[j];
//    x[j]^=x[i];
//    x[i]^=x[j];
    x[i] = x[i]+x[j];
    x[j] = x[i]-x[j];
    x[i] = x[i]-x[j];
}

void print(int x[],int length){
    for(int i = 0; i < length; i++){
        cout << x[i] << "\t";
    }
    cout <<endl;
}

/*heapSort Area*/

void maxHeapify(int r[],int heapSize,int index){
    int left = 2*index+1;
    int right = 2*index+2;
    int larger = index;
    if(r[larger] < r[left] && left < heapSize) {//不能有left=heapSize
        larger = left;
    }else larger = index;
    if(r[larger] < r[right] && right < heapSize){//不能有left=heapSize
        larger = right;
    }
    if(larger!=index){
        Swap(r,larger,index);
        maxHeapify(r,heapSize,larger);
    }
}

int lastNode(int index){
    if(index/2==0) return (index-1)/2;
    else return (index-2)/2;
}

void buildMaxHeap(int r[],int heapSize){
    for(int i = lastNode(heapSize); i >= 0; i --){
        maxHeapify(r,heapSize,i);
    }
}

void heapSort(int r[],int length){
    int heapSize = length;
    buildMaxHeap(r,length);
    for(int i = heapSize - 1; i > 0; i--){
        Swap(r,0,heapSize-1);
	cout << r[heapSize-1] << " is put at !" << heapSize-1 << endl;
        heapSize = heapSize-1;
        maxHeapify(r,heapSize,0);
    }
}

int main()
{
    int r[] = {6,7,2,3,8,4,1,9,5,0};
    print(r,len(r));
    heapSort(r,len(r));
    print(r,len(r));
    return 0;
}

　　看了这个ppt和代码应该不会不懂了！