LCS板子

#include<bits/stdc++.h>
using namespace std;
int n,m,line[100001],ans[100001],total;
int main(){
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>m;
        line[m]=i;
    }
    for(int i=1;i<=n;i++)
    {
        cin>>m;
        int search=line[m];
        if(search>ans[total])ans[++total]=search;
        else
        {
            int l=0,r=total;
            while(l<=r)
            {
                int mid=ans[(l+r)/2];
                if(search<mid)r=(l+r)/2-1;
                else
                	l=(l+r)/2+1;
            }
            ans[l]=search;
        }
    }
    cout<<total;
}