Calendar.cpp

// A C++ Program to Implement a Calendar 
// of an year 
#include<bits/stdc++.h> 
using namespace std; 

/*A Function that returns the index of the day 
of the date- day/month/year 
For e.g- 

Index	 Day 
0		 Sunday 
1		 Monday 
2		 Tuesday 
3		 Wednesday 
4		 Thursday 
5		 Friday 
6		 Saturday*/
int dayNumber(int day, int month, int year) 
{ 

	static int t[] = { 0, 3, 2, 5, 0, 3, 5, 1, 
					4, 6, 2, 4 }; 
	year -= month < 3; 
	return ( year + year/4 - year/100 + 
			year/400 + t[month-1] + day) % 7; 
} 

/* 
A Function that returns the name of the month 
with a given month number 

Month Number	 Name 
0			 January 
1			 February 
2			 March 
3			 April 
4			 May 
5			 June 
6			 July 
7			 August 
8			 September 
9			 October 
10			 November 
11			 December */
string getMonthName(int monthNumber) 
{ 
	string months[] = {"January", "February", "March", 
					"April", "May", "June", 
					"July", "August", "September", 
					"October", "November", "December"
					}; 

	return (months[monthNumber]); 
} 

/* A Function to return the number of days in 
a month 

Month Number	 Name	 Number of Days 
0			 January	 31 
1			 February 28 (non-leap) / 29 (leap) 
2			 March	 31 
3			 April	 30 
4			 May		 31 
5			 June	 30 
6			 July	 31 
7			 August	 31 
8			 September 30 
9			 October	 31 
10			 November 30 
11			 December 31 

*/
int numberOfDays (int monthNumber, int year) 
{ 
	// January 
	if (monthNumber == 0) 
		return (31); 

	// February 
	if (monthNumber == 1) 
	{ 
		// If the year is leap then February has 
		// 29 days 
		if (year % 400 == 0 || 
				(year % 4 == 0 && year % 100 != 0)) 
			return (29); 
		else
			return (28); 
	} 

	// March 
	if (monthNumber == 2) 
		return (31); 

	// April 
	if (monthNumber == 3) 
		return (30); 

	// May 
	if (monthNumber == 4) 
		return (31); 

	// June 
	if (monthNumber == 5) 
		return (30); 

	// July 
	if (monthNumber == 6) 
		return (31); 

	// August 
	if (monthNumber == 7) 
		return (31); 

	// September 
	if (monthNumber == 8) 
		return (30); 

	// October 
	if (monthNumber == 9) 
		return (31); 

	// November 
	if (monthNumber == 10) 
		return (30); 

	// December 
	if (monthNumber == 11) 
		return (31); 
} 

// Function to print the calendar of the given year 
void printCalendar(int year) 
{ 
	printf ("		 Calendar - %d\n\n", year); 
	int days; 

	// Index of the day from 0 to 6 
	int current = dayNumber (1, 1, year); 

	// i --> Iterate through all the months 
	// j --> Iterate through all the days of the 
	//	 month - i 
	for (int i = 0; i < 12; i++) 
	{ 
		days = numberOfDays (i, year); 

		// Print the current month name 
		printf("\n ------------%s-------------\n", 
			getMonthName (i).c_str()); 

		// Print the columns 
		printf(" Sun Mon Tue Wed Thu Fri Sat\n"); 

		// Print appropriate spaces 
		int k; 
		for (k = 0; k < current; k++) 
			printf("	 "); 

		for (int j = 1; j <= days; j++) 
		{ 
			printf("%5d", j); 

			if (++k > 6) 
			{ 
				k = 0; 
				printf("\n"); 
			} 
		} 

		if (k) 
			printf("\n"); 

		current = k; 
	} 

	return; 
} 

// Driver Program to check above funtions 
int main() 
{ 
	int year = 2016; 
	printCalendar(year); 

	return (0); 
}