C中的12个月日历

我用C做了12个月的日历 . 这个程序显示特定年份的12个月日历 . 该程序提示用户打印年份，并计算出（a）年份是否为闰年，以及（b）所选年份的哪一天开始 .

说明：

•main（）提示用户输入，调用您自己设计的函数来确定输入年份的开始日期 . 然后它调用函数printCalendar（）来实际打印十二个月的日历 .

•printCalendar（）有两个参数，年份编号和开始日期 . 然后循环遍历年份并调用函数printMonth（）十二次，每个月一次 .

•printMonth（）接受三个参数，即年份编号，月份编号和特定月份的开始日期，它返回下个月开始的日期编号 . 打印月必须首先调用函数printMonthName（），然后以日历格式打印出月中的日期 .

•printMonthName（）将年份编号和月份编号作为参数，打印出标识月份的行，并返回该月份的天数，同时考虑闰年 .

我按照这些说明进行了操作：

#include <stdio.h>
#include <stdlib.h>
int daysInMonth;
int getDayCode(int year);
void printCalendar(int year, int dayCode);
int getYear(void);

int getYear(void){
  int year;
  printf("Please enter a year: ");
  scanf("%i", &year);
  printf("\n");
  return year;
}

int getDayCode(int year){
  int dayCode;
  int x1, x2, x3;
          x1 = (year - 1.)/ 4.0;
          x2 = (year - 1.)/ 100.;
          x3 = (year - 1.)/ 400.;
  dayCode = (year + x1 - x2 + x3) %7;
  return dayCode;
}

main(){
  int year, dayCode;
  year = getYear();
  dayCode = getDayCode(year);
  printCalendar(year, dayCode);

}

void printCalendar(int year, int dayCode){
   int month;
   printf("        %d Monthly Calendar\n", year);
   printf(" \n");
   printf(" \n");
   for (month = 1; month <= 12; month++){
     printMonth(year, month, dayCode);
   }
}

int printMonthName(int year, int month){
  switch (month){
  case 1:
       printf("\n\nJanuary %i", year);
       daysInMonth = 31;
       return daysInMonth;
       break;
  case 2:
       printf("\n\nFebruary %i", year);
       if (year%4 == 0 && year%100 != 0 || year%400 == 0){
         //printf("This is a leap year.\n");
         daysInMonth = 29;
         return daysInMonth;
       }
      else{
        //printf("This is not a leap year.\n");
        daysInMonth = 28;
        return daysInMonth;
      }
      break;
 case 3:
      printf("\n\nMarch %i", year);
      daysInMonth = 31;
      return daysInMonth;
      break;
 case 4:
      printf("\n\nApril %i", year);
      daysInMonth = 30;
      return daysInMonth;
      break;
 case 5:
      printf("\n\nMay %i", year);
      daysInMonth = 31;
      return daysInMonth;
      break;
 case 6:
      printf("\n\nJune %i", year);
      daysInMonth = 30;
      return daysInMonth;
      break;
 case 7:
      printf("\n\nJuly %i", year);
      daysInMonth = 31;
      return daysInMonth;
      break;
 case 8:
      printf("\n\nAugust %i", year);
      daysInMonth = 31;
      return daysInMonth;
      break;
 case 9:
      printf("\n\nSeptember %i", year);
      daysInMonth = 30;
      return daysInMonth;
      break;
 case 10:
      printf("\n\nOctober %i", year);
      daysInMonth = 31;
      return daysInMonth;
      break;
 case 11:
      printf("\n\nNovember %i", year);
      daysInMonth = 30;
      return daysInMonth;
      break;
 case 12:
      printf("\n\nDecember %i", year);
      daysInMonth = 31;
      return daysInMonth;
      break;
 default:
      printf("Invalid input! Please try again!\n");
      break;
    }
}

int printMonth(int year, int month, int dayCode){
 int day;
 printMonthName(year, month);
 printf("\n\nSun  Mon  Tue  Wed  Thu  Fri  Sat\n" );
 /* advance printer to correct position for first date */
 for (day = 1; day <= 1 + dayCode * 5; day++)
 printf(" ");
 /* print the dates for one month */
 for (day = 1; day <= daysInMonth; day++){
   printf("%2d", day);
   if ((day + dayCode) % 7 > 0) /* before Sat? */
     /* move to next day in same week */
     printf("   ");
   else  /* skip to next line to start with Sun */
     printf("\n ");
   }
   /* set day_code for next month to begin */
   dayCode = (dayCode + daysInMonth % 7);
   return dayCode;
}

我把2013年作为输入年份，我的代码从星期二的1月1日开始，这是正确的 . 但它也是在周二开始的所有12个月，这是问题所在：Calendar Output 2013

请帮忙 . 我一直试图让这个工作很长一段时间 .