学步园

#include<iostream> 
using namespace std; 
#include<cstdio> 
int i,j,n,a[100001],b[100001],m,ans=0,left,k; 
int find(int r,int x) 
{ 
    int m,left=0; 
    while(left<=r) 
    { 
        m=(left+r)/2; 
        if(x>b[m])left=m+1; 
        else if(x<b[m])r=m-1; 
        else {k=left;return m;} 
    } 
    k=left; 
    return left; 
} 
int main() 
{ 
    scanf("%d",&n); 
    for(i=n;i>0;i--)scanf("%d",&a[i]); 
    for(i=1;i<=n;i++) 
    { 
        j=1;k=ans; 
        while(j<=k){   
                m=(j+k)/2;   
                if(b[m]<=a[i])j=m+1;   
                else k=m-1;   
            }  
        if(j>ans)ans++; 
        b[j]=a[i]; 
    }  
    printf("%d",ans); 
    return 0; 
}