1826: [JSOI2010]缓存交换

1826: [JSOI2010]缓存交换

https://www.lydsy.com/JudgeOnline/problem.php?id=1826

分析：

　　简单的贪心，然后调啊调。。。最近怎么了，码力大大下降，各种奇奇怪怪的bug漫天飞，以后少熬夜。

　　贪心：每次pop一定是pop最远点的点。

代码：

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;

inline int read() {
    int x=0,f=1;char ch=getchar();for(;!isdigit(ch);ch=getchar())if(ch=='-')f=-1;
    for (;isdigit(ch);ch=getchar())x=x*10+ch-'0';return x*f;
}

const int N = 100010;
#define pa pair<int,int>
#define mp(a,b) make_pair(a,b)
priority_queue< pa > q;
map<int,int> last,vis;
int nxt[N],a[N];

int main() {
    int n = read(),m = read();
    for (int i=1; i<=n; ++i) nxt[i] = n+1;
    for (int i=1; i<=n; ++i) {
        a[i] = read();
        if (last[a[i]]) nxt[last[a[i]]] = i;
        last[a[i]] = i;
    }
    int ans = 0,tot = 0;
    pa t;
    for (int i=1; i<=n; ++i) {
        if (vis[a[i]]) {q.push(mp(nxt[i],a[i]));continue;}
        if (tot == m) {
            tot --;
            while (!q.empty()) {
                t = q.top();
                q.pop(); //--居然忘记写了！！！ 
                if (vis[t.second] == 0) continue;
                vis[t.second] = 0;
                break;
            }
        }
        ans++;
        q.push(mp(nxt[i],a[i]));
        tot ++;
        vis[a[i]] = 1;
    }
    cout << ans;
    return 0;
}