1061. Dating (20)

#include <stdio.h>
#include <map>
#include <string.h>
#include <ctype.h>
using namespace std;
int main()
{
   map<char,int> ToHour;
   int i;
   for(i=0;i<=9;i++)
       ToHour['0'+i]=i;
   for(i='A';i<='N';i++)
       ToHour[i]=i-'A'+10;
   
   char Week[7][4]={ "MON", "TUE", "WED", "THU", "FRI","SAT","SUN"};

   char line1[61],line2[61],line3[61],line4[61];

   while(gets(line1)!=NULL)
   {
       gets(line2);
       gets(line3);
       gets(line4);
       int fir=1;
       for(i=0;i<(strlen(line1)<strlen(line2)?strlen(line1):strlen(line2));i++)
       {
           if(line1[i]==line2[i]&&line1[i]>='A'&&line1[i]<='G')
           {
                  printf("%s",Week[line1[i]-'A']);
                  break;   
           }
       }

       for(++i;i<(strlen(line1)<strlen(line2)?strlen(line1):strlen(line2));i++)
       {
           if(line1[i]==line2[i]&&((line1[i]>='A'&&line1[i]<='N')||(line1[i]>='0'&&line1[i]<='9')))
           {
                      printf(" %02d",ToHour[line1[i]]);
                       break;  
           }
       }

        for(i=0;i<(strlen(line3)<strlen(line4)?strlen(line3):strlen(line4));i++)
        {
            if(line3[i]==line4[i]&&isalpha(line3[i]))
            {
                printf(":%02d\n",i);
                break;
            }
        }
   }
   
}