NOIP 考前DP 复习

 1 #include <cstdio>
 2 const int Maxn=1010;
 3 int a[Maxn],Pos[Maxn],F[Maxn],n,Ans;
 4 inline int Max(int x,int y) {return x>y?x:y;}
 5 inline int Find(int x)
 6 {
 7     int l=1,r=Ans,Res;
 8     while (l<=r)
 9     {
10         int mid=(l+r)>>1;
11         if (a[Pos[mid]]<x) Res=mid,l=mid+1;  else r=mid-1;
12     }
13     return Res;
14 }
15 int main()
16 {
17     scanf("%d",&n);
18     for (int i=1;i<=n;i++) scanf("%d",&a[i]);
19     F[1]=1; Pos[1]=1; Ans=1;
20     for (int i=2;i<=n;i++)
21     {
22         int t=Find(a[i]);
23         Pos[t+1]=i;
24         F[i]=t+1;
25         Ans=Max(Ans,F[i]);
26     }
27     printf("%d\n",Ans);
28     return 0;
29 }