hdu 1159 dp LCS

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <string>
#include <cstring>
using namespace std;
const int MAXN = 1E3+10;

int dp[MAXN][MAXN];

int main()
{
    string s1,s2;
    while(cin>>s1>>s2){
        memset(dp,0,sizeof(dp));
        int n1 = s1.length();
        int n2 = s2.length();
        
        for(int i=1;i<=n1;i++){
            for(int j=1;j<=n2;j++){
                if(s1[i-1]==s2[j-1]){
                    dp[i][j] = dp[i-1][j-1]+1;
                }else{
                    dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
                }
            }
        }
       cout<<dp[n1][n2]<<endl;
    }
    return 0;
}