堆的建立与删除

堆的实现

---

class Heap {
private:
    int *data, size;
public:
    Heap(int length_input) {
        data = new int[length_input];
        size = 0;
    }
    ~Heap() {
        delete[] data;
    }
    void push(int value){

    }

};

此处实现一个大根堆，根节点的值最大

---

堆的插入

具体原理略

void push(int value) {
    data[size] = value;
    int current = size;
    int father = (current - 1) / 2;
    while (data[current] > data[father]) {
        swap(data[current], data[father]);
        current = father;
        father = (current - 1) / 2;
    }
    size++;
}

---

堆的删除与上滤
首先找出当前最大的值——确认其是自身，左孩子还是右孩子
然后进行交换
再从交换后的节点出发，递归调用

void update(int pos,int n){
    int lchild=2*pos+1,rchild=2*pos+2;
    int max_value=pos;
    if(lchilddata[max_value]){
        max_value=lchild;
    }
    if(rchilddata[max_value]){
        max_value=rchild;
    }
    if(max_value!=pos){
        swap(data[pos],data[max_value]);
        update(max_value,n);
    }

}
void pop(){
    swap(data[0],data[size-1]);
    size--;
    update(0,size);
}