BZOJ 1528: [POI2005]sam-Toy Cars、BZOJ 1826: [JSOI2010]缓存交换

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
#include <iostream>
#include <cctype>
using namespace std;
inline char nc() {
    static char buf[100000], *p1, *p2;
    return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;
}
inline int read() {
    int x=0;char ch=nc();
    while(!isdigit(ch))ch=nc();
    while(isdigit(ch)){x=(x<<3)+(x<<1)+ch-‘0‘;ch=nc();}
    return x;
}
struct node {
    int next,x;
    bool operator < (const node &x) const {
        return next<x.next;
    }
};
int head[510000],a[510000],next[510000];
bool vis[510000];
priority_queue<node>q;
int main() {
    /*freopen("toy.in","r",stdin);
    freopen("toy.out","w",stdout);*/
    int n,k,p;
    n=read(),k=read(),p=read();
    for(int i=1;i<=p;i++)a[i]=read();
    for(int i=1;i<=n;i++)head[i]=p+1;
    for(int i=1;i<=p;i++)
    {
        next[head[a[i]]]=i;
        head[a[i]]=i;
    }
    int now=0,ans=0;
    for(int i=1;i<=p;i++) if(!next[i])next[i]=p+1;
    for(int i=1;i<=p;i++) {
        if(vis[a[i]]) {
            node tmp;
            tmp.x=a[i];
            tmp.next=next[i];
            q.push(tmp);
        }
        else if(now<k) {
            now++;
            node tmp;
            tmp.x=a[i];
            tmp.next=next[i];
            q.push(tmp);
            vis[a[i]]=1;
            ans++;
        }
        else {
            node tmp=q.top();
            while(!vis[tmp.x]) {
                //q.pop();
                tmp=q.top();
            }
            q.pop();
            vis[tmp.x]=0;
            tmp.x=a[i];
            tmp.next=next[i];
            ans++;
            q.push(tmp);
            vis[a[i]]=1;
        }
    }
    printf("%d\n",ans);
 
}