P1311 [NOIP2011 提高组] 选择客栈

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>
using namespace std ;
 
const int N=2e5+32;
 int mn[N][20],n,p;
 int f[N],g[N],a[N],c[N],cnt[N];
 
 void init(){
     int i,j;
    
     for(i=1;i<=n;i++) mn[i][0]=c[i];
     for(j=1;j<20;j++)
      for(i=1;i+(1<<j)-1<=n;i++){
          mn[i][j]=min(mn[i][j-1],mn[i+(1<<(j-1))][j-1]);
      }
 }
 int q(int l,int r){
     int t=log2(r-l+1);
     return min(mn[l][t],mn[r-(1<<t)+1][t]);
 }
 void solve(){
     int i;
     for(i=1;i<=n;i++){
         cin>>a[i]>>c[i];
         if(g[a[i]]==0) g[a[i]]=i;
     }
     init();
     for(i=1;i<=n;i++){
         f[i]=f[g[a[i]]];
         if(i==g[a[i]]){ cnt[a[i]]++; continue; }
         if(q(g[a[i]],i)<=p) f[i]=cnt[a[i]];
         g[a[i]]=i;
         cnt[a[i]]++;
     }
     int t=0;
     for(i=1;i<=n;i++) t+=f[i];
     cout<<t;
 }
 main(){
     int k;
     cin>>n>>k>>p;
     solve();
 }