日期小于的几种的情况下判断一下即可, 斜杠当做一个字符读取掉即可
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 0;
signed main() {
int a, b, c;
char ch;
cin >> a >> ch;
cin >> b >> ch;
cin >> c;
if (b < 4)
cout << "Yes\n";
else if (b == 4 && c <= 30)
cout << "Yes\n";
else
cout << "No\n";
return 0;
}