C++-LUOGU1059-明明的随机数[堆排序]

就是秀一波操作辣

#include <iostream>
using namespace std;
const int N=1e3+20;
int ans[N],cnt=1;
struct heap{
    int a[N],n;    
    int top(){return a[1];}
    bool empty(){return n==0;}
    void push(int x){a[++n]=x,up(n);}
    void pop(){swap(a[1],a[n--]),down(1);}
    void up(int x){
        for(int f;x>1,f=x>>1;x=f){
            if(a[f]>a[x])swap(a[f],a[x]);
            else return;
        }
    }
    void down(int x){
        for(int ls,rs,p;(x<<1)<=n;x=p){
            ls=x<<1,rs=x<<1|1;
            p=rs<=n&&a[rs]<a[ls]?rs:ls;
            if(a[p]<a[x])swap(a[p],a[x]);
            else return;
        }
    }
};
heap q;
int main(){
    int n;cin>>n; 
    for(int a;n--;)cin>>a,q.push(a);
    for(int a;!q.empty();){
        a=q.top(),q.pop();
        if(ans[cnt-1]!=a)ans[cnt++]=a;
    }
    cout<<cnt-1<<endl;
    for(int i=1;i<cnt;i++)cout<<ans[i]<<" ";
    return 0;
}