Common Subsequence

POJ-1458

//最长公共子序列问题
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<string>
using namespace std;
string a,b;
int dp[1003][1003];
int main(){
    while(cin>>a>>b){
        int lena=a.length();
        int lenb=b.length();
        memset(dp,0,sizeof(dp));
        for(int i=1;i<=lena;i++){
            for(int j=1;j<=lenb;j++){
                if(a[i-1]==b[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[lena][lenb]<<endl;
    }
    return 0;
}