1061. Dating

#include<cstdio>
#include<cctype>
using namespace std;
char*day[7]={"MON","TUE","WED","THU","FRI","SAT","SUN"};
bool ishour(char c){return c>='0'&&c<='9'||c>='A'&&c<='N';}
bool isday(char c){return c>='A'&&c<='G';}
int main()
{
    char s[4][70],i,c;
    scanf("%s%s%s%s",s[0],s[1],s[2],s[3]);
    for(i=0;;++i)
        if(s[0][i]==s[1][i]&&isday(s[0][i])){
                printf("%s",day[s[0][i]-'A']);
                break;
        }
    for(++i;;++i)
        if(s[0][i]==s[1][i]&&ishour(c=s[0][i])){
                printf(" %02d:",(c>='0'&&c<='9')?c-'0':c-'A'+10);
                break;
        }
    for(i=0;;++i)
        if(s[2][i]==s[3][i]&&isalpha(s[3][i])){
            printf("%02d",i);
            break;
        }
    return 0;
}

注意每次的边界条件