HDOJ 1159

思路：dp[i][j]表示str1的第i-1个字符和str2的第j-1个字符的最大的LCS，str[i-1] == str[j-1]时，dp[i][j] = dp[i-1][j-1] + 1 ; else : dp[i-1][j-1] = max(dp[i-1][j],dp[i][j-1]) .

#include<iostream>
#include<cstdio>
#include<string>
#include<cstring>
using namespace std;
string str1, str2;
int dp[2005][2005];
int main(){
    /* freopen("in.c", "r", stdin); */
    while(cin >> str1 >> str2){
        memset(dp, 0, sizeof(dp));
        for(int i = 1;i <= str1.size();i ++){
            for(int j = 1;j <= str2.size();j ++){
                if(str1[i-1] == str2[j-1]) dp[i][j] = dp[i-1][j-1] + 1;
                else dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
            }
        }
        printf("%d\n", dp[str1.size()][str2.size()]);
        str1.clear(), str2.clear();
    }
    return 0;
}