HDU 1159 Common Subsequence

/*
经典的动态规划
*/
#include <iostream>
using namespace std;
char str1[1000];
char str2[1000];
int dp[1001][1001];
int main(){
    while(cin >> str1 >> str2){
        int len1 = strlen(str1);
        int len2 = strlen(str2);
        int max = -1;
        memset(dp,0,sizeof(dp));
        for(int i = 0; i < len1; i++){
            for(int j = 0; j < len2; j++){
                if(str1[i] == str2[j]){
                    dp[ i + 1][j + 1] = dp[i][j] + 1;
                } else {
                    dp[i + 1][j + 1] = dp[i][j + 1] > 
                        dp[i + 1][j] ? dp[i][j + 1] : 
                        dp[i + 1][j];
                }
                if(max < dp[i+1][j+1])
                    max = dp[i+1][j+1];
            }
        }
        cout << max << endl;
    }
    return 0;
}