luogu1540 [NOIp2011]机器翻译 (队列)

 #include<bits/stdc++.h>
 #define pa pair<int,int>
 #define CLR(a,x) memset(a,x,sizeof(a))
 using namespace std;
 typedef long long ll;
 const int maxn=,maxm=;

 inline ll rd(){
     ll x=;char c=getchar();int neg=;
     while(c<''||c>''){if(c=='-') neg=-;c=getchar();}
     while(c>=''&&c<='') x=x*+c-'',c=getchar();
     return x*neg;
 }

 queue<int> q;
 int N,M;
 bool ins[maxn];

 int main(){
     //freopen("","r",stdin);
     int i,j,k,ans=;
     M=rd(),N=rd();
     for(i=;i<=N;i++){
         int x=rd();
         if(!ins[x]){
             ans++;
             if(q.size()>=M){
                 ins[q.front()]=;q.pop();
             }
             ins[x]=;q.push(x);
         }
     }
     printf("%d\n",ans);
     return ;
 }