【BZOJ】【3831】【POI2014】Little Bird

 1 //BZOJ 3831
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<cstdlib>
 5 #include<iostream>
 6 #include<algorithm>
 7 #define rep(i,n) for(int i=0;i<n;++i)
 8 #define F(i,j,n) for(int i=j;i<=n;++i)
 9 #define D(i,j,n) for(int i=j;i>=n;--i)
10 using namespace std;
11 const int N=1000086,INF=~0u>>2;
12 //#define debug
13 int n,m,a[N],f[N],q[N];
14 
15 int main(){
16     #ifndef ONLINE_JUDGE
17     freopen("file.in","r",stdin);
18     #endif
19     scanf("%d",&n);
20     F(i,1,n) scanf("%d",&a[i]);
21     
22     scanf("%d",&m);
23     while(m--){
24         int l=0,r=0,k=0;
25         memset(q,0,sizeof q);
26         
27         scanf("%d",&k);
28         f[0]=f[1]=0;
29         q[r++]=1;
30         F(i,2,n){
31             while(q[l]+k<i && l<r) l++;
32             f[i]=f[q[l]] + ((a[q[l]]<=a[i]) ? 1 : 0) ;
33             while( ((f[i]<f[q[r-1]]) || (f[i]==f[q[r-1]] && a[i]>=a[q[r-1]])) && l<r) r--;
34             q[r++]=i;
35         }
36         printf("%d\n",f[n]);
37     }
38     return 0;
39 }