D. Dog Show 2017-2018 ACM-ICPC, NEERC, Southern Subregional Contest, qualification stage (Online Mirror, ACM-ICPC Rules, Teams Preferred)

http://codeforces.com/contest/847/problem/D

巧妙的贪心

仔细琢磨。。。

像凸包里的处理

 #include <cstdio>
 #include <cstdlib>
 #include <cmath>
 #include <cstring>
 #include <time.h>
 #include <string>
 #include <set>
 #include <map>
 #include <list>
 #include <stack>
 #include <queue>
 #include <vector>
 #include <bitset>
 #include <ext/rope>
 #include <algorithm>
 #include <iostream>
 using namespace std;
 #define ll long long
 #define minv 1e-6
 #define inf 1e9
 #define pi 3.1415926536
 #define E  2.7182818284
 const ll mod=1e9+;//
 const int maxn=2e5+;

 vector<int>b;
 vector<int>::iterator j;
 int a[maxn];

 priority_queue<int>s;

 int main()
 {
     int n,m,i,a,sum=,g=;
     scanf("%d%d",&n,&m);
     for (i=;i<=min(m-,n);i++)
     {
         scanf("%d",&a);
         if (a>=m)
             continue;
         while (!s.empty() && s.top()>=m-i)
         {
             s.pop();
             g--;
         }
         s.push(a-i);
         g++;
         sum=max(sum,g);
     }
     cout<<sum;
     return ;
 }