[Poi2010]Monotonicity 2 (线段树优化DP)

 1 #include<cmath>
 2 #include<ctime>
 3 #include<cstdio>
 4 #include<cstdlib>
 5 #include<cstring>
 6 #include<iostream>
 7 #include<algorithm>
 8 # define maxn 500010
 9 # define lson rt<<1,l,mid
10 # define rson rt<<1|1,mid+1,r
11 using namespace std;
12 int n,K;
13 int a[maxn];
14 int hao[maxn],ord[maxn];
15 int lim;
16 void init(){
17     scanf("%d%d",&n,&K);
18     for(int i=1;i<=n;i++) scanf("%d",&a[i]),lim=max(lim,a[i]);
19     char s[2];
20     for(int i=1;i<=K;i++){
21         scanf("%s",&s);
22         if(s[0]==‘<‘) hao[i]=1;
23         if(s[0]==‘=‘) hao[i]=2;
24         if(s[0]==‘>‘) hao[i]=3;
25     }
26     for(int i=1;i<=n;i++)
27         ord[i]=hao[(i-1)%K+1];
28 }
29 int f[maxn];
30 struct XDS{
31     int mx[4000010];
32     void add(int now,int w,int rt,int l,int r){
33         //cout<<now<<"  "<<w<<"  "<<rt<<"  "<<l<<"  "<<r<<endl;
34         if(l==r){
35             mx[rt]=max(mx[rt],w);
36             return;
37         }
38         int mid=(l+r)>>1;
39         if(now<=mid){
40             add(now,w,lson);
41         }
42         if(now>mid){
43             add(now,w,rson);
44         }
45         mx[rt]=max(mx[rt<<1],mx[rt<<1|1]);  
46     }
47     int find(int left,int right,int rt,int l,int r){
48         if(left<=l && r<=right){
49             return mx[rt];
50         }
51         int mid=(l+r)>>1;
52         int ans=0;
53         if(left<=mid){
54             ans=max(ans,find(left,right,lson));
55         }
56         if(right>mid){
57             ans=max(ans,find(left,right,rson));
58         }
59         return ans;
60     }
61 };
62 XDS da,xiao;
63 int deng[1000010];
64 void fang(int now,int w,int od){
65 //  cout<<"now== "<<now<<"  "<<w<<" "<<od<<endl;
66     if(od==1){
67         da.add(now,w,1,0,lim);
68     }
69     if(od==3){
70         xiao.add(now,w,1,0,lim);
71     }
72     if(od==2){
73         deng[now]=max(deng[now],w);
74     }
75 }
76 int main(){
77     //freopen("a.in","r",stdin);
78     //freopen("mot.in","r",stdin); freopen("mot.out","w",stdout);
79     init();
80     for(int i=1;i<=n;i++){
81         int x;
82         x=deng[a[i]]+1;
83         fang(a[i],x,ord[x]);
84         x=da.find(0,a[i]-1,1,0,lim)+1;
85         fang(a[i],x,ord[x]);
86         x=xiao.find(a[i]+1,lim,1,0,lim)+1;
87         fang(a[i],x,ord[x]);
88     }
89     int ans=0;
90     for(int i=0;i<=lim;i++){
91         ans=max(deng[i],ans);
92     }
93     ans=max(ans,da.find(0,lim,1,0,lim));
94     ans=max(ans,xiao.find(0,lim,1,0,lim));
95     cout<<ans<<endl;
96     return 0;
97       
98 }