5582 공통부분 문자열

#include <stdio.h>
#include <string>
#include <iostream>
 
using namespace std;
 
string str1;
string str2;
 
int dp[4004][4004] = { 0 };
 
int main() {
    cin >> str1 >> str2;
 
    str1 = "0" + str1;
    str2 = "0" + str2;
 
    int len1 = str1.size() - 1;
    int len2 = str2.size() - 1;
 
    int rst = 0;
    for (int i = 1; i <= len2; i++) {
        for (int j = 1; j <= len1; j++) {
            if (str2[i] == str1[j]) {
                dp[i][j] = dp[i - 1][j - 1] + 1;
 
                if (rst < dp[i][j])
                    rst = dp[i][j];
            }
        }
    }
 
    printf("%d", rst);
}