题解

#include<iostream>
#include<queue>
using namespace std;
queue<int>q;
int m,n,x,ans;
bool t[1010]; 
int main(){
    cin>>m>>n;
    for(int i=1;i<=n;i++){
        cin>>x;
        if(t[x]==1){
            continue;
        }     
        if(q.size()>=m){
            t[q.front()]=0; 
            q.pop();     
        }
        q.push(x); 
        t[x]=1;
        ans++;
    }
    cout<<ans;
    return 0;
}