AC日记——二叉堆练习3 codevs 3110

#include <cstdio>
#include <iostream>
#include <algorithm>

using namespace std;

class T_heap {
    private:
        int heap[500001],n;
        
    public:
        void up(int now)
        {
            if(now<=1) return ;
            int front=now>>1;
            if(heap[front]>heap[now])
            {
                swap(heap[front],heap[now]);
                up(front);
            }
        }
        
        void down(int now)
        {
            if(now>n) return;
            int vlc,vrc,next=now;
            bool blc,brc;
            if((now<<1)<=n) blc=true,vlc=heap[now<<1];
            else blc=false;
            if((now<<1|1)<=n) brc=true,vrc=heap[now<<1|1];
            else brc=false;
            if(blc)
            {
                if(vlc<heap[next])
                {
                    next=now<<1;
                }
            }
            if(brc)
            {
                if(vrc<heap[next])
                {
                    next=now<<1|1;
                }
            }
            if(next!=now)
            {
                swap(heap[next],heap[now]);
                down(next);
            }
        }
        
        void push(int cur_)
        {
            n++;
            heap[n]=cur_;
            up(n);
        }
        
        void pop()
        {
            heap[1]=heap[n];
            n--;
            down(1);
        }
        
        int top()
        {
            return heap[1];
        }
};
class T_heap heap;

int n,ai;

int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&ai);
        heap.push(ai);
    }
    for(int i=1;i<=n;i++)
    {
        printf("%d ",heap.top());
        heap.pop();
    }
    return 0;
}