题解 | #Coincidence#

#include <bits/stdc++.h>
using namespace std;

int main() {
    string s1, s2;
    cin >> s1 >> s2;
    if (s1 == "" || s2 == "") {
        cout << 0 << endl;
        return 0;
    }
    int m = s1.length();
    int n = s2.length();
    //开始dp
    int dp[m + 1][n + 1];
    //初始化dp
    for (int i = 0; i <= m; i++)
        for (int j = 0; j <= n ; j++)
            dp[i][j] = 0;

    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            if (s1[i-1] == s2[j-1]) {
                dp[i][j] = dp[i - 1][j - 1] + 1;
            } else {
                dp[i][j] = max(dp[i][j - 1], dp[i - 1][j]);
            }
        }
    }
    cout << dp[m][n];
}
// 64 位输出请用 printf("%lld")