Question

Please write a C program to implement the calendar of the year (after the year 1900) you specify. For example, when you input 1900, the program print the calendar of year 1900 as the figure (partial) down below. Hint 1: Jan. 1st, 1900 is Monday. Hint 2: You will need to consider the case of Leap Year where there are 29 days in the month of February. In common years there are 28 days in the month of February. For the determination of Leap Year, you are referred to https://en.wikipedia.org/wiki/Leap_year.

Answer 1

#include<stdio.h>

int num[]={0,31,28,31,30,31,30,31,31,30,31,30,31};
char *month[]=
{
   " ",
   "\n\n\nJanuary",
   "\n\n\nFebruary",
   "\n\n\nMarch",
   "\n\n\nApril",
   "\n\n\nMay",
   "\n\n\nJune",
   "\n\n\nJuly",
   "\n\n\nAugust",
   "\n\n\nSeptember",
   "\n\n\nOctober",
   "\n\n\nNovember",
   "\n\n\nDecember"
};

int getCode(int year)
{
   int code;
   int d1, d2, d3;
  
   d1 = (year - 1.)/ 4.0;
   d2 = (year - 1.)/ 100.;
   d3 = (year - 1.)/ 400.;
   code = (year + d1 - d2 + d3) %7;
   return code;
}

int leapYear(int year)
{
   if(year% 4 == 0 && year%100 != 0 || year%400 == 0)
   {
       num[2] = 29;
       return 1;
   }
   else
   {
       num[2] = 28;
       return 0;
   }
}

void dispCalender(int year, int code)
{
   int i, day;
   for ( i = 1; i <= 12; i++ )
   {
       printf("%s", month[i]);
       printf("\n\nSun Mon Tue Wed Thu Fri Sat\n" );

       for ( day = 1; day <= 1 + code * 5; day++ )
       {
           printf(" ");
       }

       for ( day = 1; day <= num[i]; day++ )
       {
           printf("%2d", day );

           if ( ( day + code ) % 7 > 0 )
               printf("   " );
           else
               printf("\n " );
       }
           code = ( code + num[i] ) % 7;
   }
}

int main(void)
{
   int year, code, leapyear;
   printf("Please enter a year after 1900 : ");
   scanf("%d", &year);
   code = getCode(year);
   leapYear(year);
   dispCalender(year, code);
   printf("\n");
}

main.c Please enter a year after 1900 : 2019 January Sun Mon 6 13 20 27 7 14 21 28 Tue Wed Thu Fri Sat 1 2 3 4 8 9 10 11 12 15 16 17 18 19 22 23 24 25 26 29 30 31 February Sun Mon 3 10 17 24 4 11 18 25 Tue Wed Thu Fri Sat 1 2 5 6 7 8 9 12 13 14 15 16 19 20 21 22 23 26 27 28 March Sun Mon Tue Wed Thu Fri Sat 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16