就是秀一波操作辣
1 #include <iostream> 2 using namespace std; 3 const int N=1e3+20; 4 int ans[N],cnt=1; 5 struct heap{ 6 int a[N],n; 7 int top(){return a[1];} 8 bool empty(){return n==0;} 9 void push(int x){a[++n]=x,up(n);} 10 void pop(){swap(a[1],a[n--]),down(1);} 11 void up(int x){ 12 for(int f;x>1,f=x>>1;x=f){ 13 if(a[f]>a[x])swap(a[f],a[x]); 14 else return; 15 } 16 } 17 void down(int x){ 18 for(int ls,rs,p;(x<<1)<=n;x=p){ 19 ls=x<<1,rs=x<<1|1; 20 p=rs<=n&&a[rs]<a[ls]?rs:ls; 21 if(a[p]<a[x])swap(a[p],a[x]); 22 else return; 23 } 24 } 25 }; 26 heap q; 27 int main(){ 28 int n;cin>>n; 29 for(int a;n--;)cin>>a,q.push(a); 30 for(int a;!q.empty();){ 31 a=q.top(),q.pop(); 32 if(ans[cnt-1]!=a)ans[cnt++]=a; 33 } 34 cout<<cnt-1<<endl; 35 for(int i=1;i<cnt;i++)cout<<ans[i]<<" "; 36 return 0; 37 }