4967. 翻转

 4967. 翻转 - AcWing题库

#include <iostream>
#include <string>

using namespace std;

int main() {
	int T;
	cin >> T;
	while (T--) {
		string t, s;
		cin >> t >> s;
		int n = s.size();
		if (t[0] != s[0] || t[n - 1] != s[n - 1]) {
			cout << -1 << endl;
			continue;
		}
		int cnt = 0;
		for (int i = 1; i < n - 1; i++) {
			if (s[i] != t[i]) {
				if (s[i - 1] == s[i] || s[i + 1] == s[i]) {
					cnt = -1;
					break;
				}
				s[i] = t[i];
				cnt++;
			}
		}
		cout << cnt << endl;
	}
	return 0;
}