华为机试：公共子串计算

#include <iostream>
#include <string>
#include <vector>
using namespace std;

int main() {
    string str1;
    string str2;
    cin >> str1 >> str2;
    int n = str1.length();
    int m = str2.length();
    vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
    int max = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (str1[i - 1] == str2[j - 1]) {
                dp[i][j] = dp[i - 1][j - 1] + 1;
            }
            else {
                dp[i][j] = 0;
            }
            if (dp[i][j] > max) {
                max = dp[i][j];
            }
        }
    }
    cout << max << endl;
    return 0;
}