日历.cpp

一个自己编写简单的程序

#include <stdio.h>
#include <math.h>
#include <iostream.h>
void printmonth(int m);
void printhead(int m);
int daysofmonth(int m);
int firstday(int y);
int year,weekday;

void main()
{
  int i;
  cout<<"请输入年份:";
  cin>>year;
  weekday=firstday(year);
  cout<<endl<<endl;
  cout<<"              "<<year<<"年"<<endl;
  for (i=1;i<=12;i++)
      { 
	      printmonth(i);
		  cout<<endl;
	  }
  cout<<endl<<endl;
  cin>>i;
}

void printmonth(int m)
{
  int i,days;
  printhead(m);
  days=daysofmonth(m);
  for (i=1;i<=days;i++)
      {
	     printf("%5d",i);
		 weekday=(weekday+1)%7;
		 if (weekday==0)  printf("\n  ");  
      }
}

void printhead(int m)
{
  int i;
  if (m<10)
     cout<<endl<<m<<"月  日   一   二   三   四   五   六"<<endl;
  else
     cout<<endl<<m<<"月 日   一   二   三   四   五   六"<<endl;
  printf("  ");
  for (i=0;i<weekday;i++)
      printf("     ");
}
                
int daysofmonth(int m)
{
  switch (m)
  {
    case 1:
	case 3:
	case 5:
	case 7:
	case 8:
	case 10:
	case 12:return 31;
	case 4:
	case 6:
	case 9:
	case 11:return 30;
	case 2:if (((year%4==0 && year%100!=0)||year%400==0))
	          return 29;
           else 
			  return 28;
    default:  return 0;
  }
}

int firstday(int y)
{
  double s;
  s=floor(year-1+(year-1)/4.0-(year-1)/100.0+(year-1)/400.0+1);
  return (int)s%7;
}