UVA Solution 150 - Double Time - Solution in C++ | Volume 1

UVA Solution 150 - Double Time - Solution in C++ | Volume 1

Problem Name: Double Time
Problem Number : UVA - 150
Online Judge : UVA Online Judge Solution
Volume: 1
Solution Language : C plus plus

UVA Solution 150 Code in CPP:

#include <stdio.h> 
#include <algorithm>
#include <iostream>
using namespace std;
int aDays[] =  {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365};
int aLeapDays[] = {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366};
const string dayName[] = {"Sunday", "Monday", "Tuesday",
        "Wednesday", "Thursday", "Friday", "Saturday"};
const string monthName[] = {"January", "February", "March",
        "April", "May", "June", "July", "August", "September",
        "October", "November", "December"};
int isLeapYear(int y, int old) {
 if(old) return y%4 == 0;
 return (y%4 == 0 && y%100 != 0) || y%400 == 0;
}
int toDays(int y, int m, int d, int old) {
 y--;
 int days = y * 365 + y / 4 + (old ? 0 : (y / 400 - y/100));
 days += m > 2 ? isLeapYear(y+1, old) : 0;
 return days + aDays[m - 1] + d - 1 - (old * 2);
}

int main() {
 string str;
 while(cin >> str) {
  if(str == "#") break;
  int day, d, m, y;
  day = find(dayName, dayName + 7, str) - dayName;
  cin >> d >> str >> y;
  m = find(monthName, monthName + 12, str) - monthName + 1;
  int days = toDays(y, m, d, 1), old;
  if(day == (days + 1)%7) {
   // old -> new
   y = days / (400 * 365 + 100 - 3) * 400;
   days %= 400 * 365 + 100 - 3;
   if(days == 100 * 365 + 25 - 1) {
    y += 300;
    days -= (100 * 365 + 25 - 1) * 3;
   } else {
    y += days / (100 * 365 + 25 - 1) * 100;
    days %= 100 * 365 + 25 - 1;
   }
   old = 0;
  } else {
   // new -> old
   days = toDays(y, m, d, 0) + 2;
   y = 0;
   old = 1;
  }
  y += days / (4 * 365 + 1) * 4;
  days %= (4 * 365 + 1);
  if(days == 365 * 4) {
   y += 3;
   days -= 365 * 3;
  } else {
   y += days / 365;
   days %= 365;
  }
  y++;
  int *pDays = isLeapYear(y, old) ? aLeapDays : aDays;
  
  for(m = 0; m < 12 && pDays[m] <= days; m++);
  
  d = days - pDays[m - 1] + 1;
  day = (toDays(y, m, d, old) + 1) %7;
  printf("%s %d%s %s %d\n", dayName[day].c_str(), d, old ? "*" : "", monthName[m-1].c_str(), y);
 }
 return 0;
}