UNACCEPTED代码奉上:

#include<bits/stdc++.h>
using namespace std;
int main(){
    const int d=13;
    int mm,dd,days[d]={-1,31,28,31,30,31,30,31,31,30,31,30,31},g=0,flag=0;
    if(mm<=12){
        if(dd<=days[mm]) {printf("0");return 0;}
        else ++g;
    }
    else{
        if(mm%10<=2){
            if(days[mm%10+10]>=dd) ++g;
            else flag=1,g+=2;
        }
        if(flag){
            if(days[mm%10]>=dd) g=1;
        }
    }
    printf("%d",g);
    return 0;
}

咋的回事？