最大公共子串长度（蓝桥杯17I）

#include<iostream>
#include<string>
using namespace std;
int main() {
	string s1, s2;
	getline(cin,s1);
	getline(cin,s2);
	int arr[100][100];
	int maxn = 0;
	for (int i = 0; i < s1.size();i++) {
		for (int j = 0; j < s2.size();j++) {
			if (i != 0 || j != 0) {
				if (s1[i] == s2[j] && arr[i - 1][j - 1] == 0) {
					arr[i][j] = 1;
				}
				else if (s1[i] == s2[j] && arr[i - 1][j - 1] > 0) {
					arr[i][j] = arr[i - 1][j - 1] + 1;
				}
			}
			else {
				if (s1[i] == s2[j]) {
					arr[i][j] = 1;
				}
			}
			maxn = max(arr[i][j],maxn);
		}
	}
	cout << maxn;
	return 0;
}