RT，求各位大佬帮忙看看QAQ

#include<bits/stdc++.h>
using namespace std;
string s;
int m,d,ans;
int a[]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int main()
{
	cin>>s;
	m = (s[0]-'0')*10+s[1]-'0';
	d = (s[3]-'0')*10+s[4]-'0';
	if(!d) 
	{
		ans++;
		d = 10;
	}
	if(!m)
	{
		ans++;
		m = 10;
	}
	if(m>12)
	{
		ans++;
		if(s[0]==1) m = 12;
		else if(m%10<3) m =10+m%10;
		else m%=10;
	}
	if(d>31)
	{
		ans++;
		d = d%10+10;
	}
	if(d>a[m]) ans++;
	printf("%d",ans);
	return 0;
 }