Common Subsequence POJ - 1458 最长公共子序列 线性DP

#include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
#include <cstdio>
#define MAX 1005
using namespace std;
int ans[MAX][MAX];
int main(){
    string s1,s2;
    while(cin>>s1>>s2)
    {    
        memset(ans,0,sizeof ans);
        int len1=s1.size(); int len2=s2.size();
        for(int i=1;i<=len1;i++)
            for(int j=1;j<=len2;j++){
                if(s1[i-1]==s2[j-1])
                    ans[i][j]=ans[i-1][j-1]+1;
                else
                    ans[i][j]=max(ans[i-1][j],ans[i][j-1]);
            }
        cout<<ans[len1][len2]<<endl;
    }
    return 0;
}