C语言打印万年历

Date.h文件如下：

//打印万年历从1900年起
#ifndef DATE_H
#define DATE_H
#include <string.h>
#define OUT_OF_YEAR -1
//是否是闰年
bool isLeap(int year){
	if(year<1900) return OUT_OF_YEAR;
	return (year%4==0)&&(year%100!=0)||(year%400==0);
}
//从year到1900年间闰年个数
int  LeapYearNum(int year){
	if(year<1900) return OUT_OF_YEAR;
	int LeapYear=0;
	for (int i=1900;i<=year;i++)
	{
		if(isLeap(i)){
			++LeapYear;
		}	
	}
	return LeapYear;
}
//到year开始到1900年的天数
int GetDayNum(int year){
	if(year<1900) return OUT_OF_YEAR;
	return LeapYearNum(year)+(year-1900)*365;
}
//year年,mounth月的天数
int GetDayOfMouth(int year,int mounth){
	if (year<1900 || mounth<1||mounth>12) return OUT_OF_YEAR;
	int dayNum=0;
	switch (mounth)
	{
	case 1:
	case 3:
	case 5:
	case 7:
	case 8:
	case 10:
	case 12:
		dayNum=31;
		break;
	case 4:
	case 6:
	case 9:
	case 11:
		dayNum=30;
		break;
	case 2:
		if(isLeap(year)){
			dayNum=29;
		}else{
			dayNum=28;
		}
		break;
	default:
		dayNum=0;
	}
	return dayNum;
}
//到1900年的天数
int getDay(int year,int mouth){
	int mouthDay=0;
	for (int i=1;i<mouth;i++)
	{
		mouthDay+=GetDayOfMouth(year,i);
	}
	return GetDayNum(year)+mouthDay;
}
int getWeek(int year,int mouth){
	return getDay(year,mouth)%7+1;
}
//得到星期英文缩写
char* getWeekChar(int i){
	if (i<1||i>7) return "";
	char *WeekChar="   ";
	switch(i){
	case 1:
		WeekChar="Mon";
		break;
	case 2:
		WeekChar="Tue";
		break;
	case 3:
		WeekChar="Wed";
		break;
	case 4:
		WeekChar="Thu";
		break;
	case 5:
		WeekChar="Fri";
		break;
	case 6:
		WeekChar="Sat";
		break;
	case 7:
		WeekChar="Sun";
		break;
	default:
		WeekChar="";
	}
	return WeekChar;

}
//打印月份
void printMouth(int year,int mouth){
	int startWeek=getWeek(year,mouth);
	int days=GetDayOfMouth(year,mouth);
	printf("*********************%d年%d月******************************
",year,mouth);
	int dayIndex=1;
	printf("
");
	for (int i=1;i<=7;i++)
	{
		printf(" %s	",getWeekChar(i));
	}
	printf("
");
	for (int i=1;i<=50;i++)
	{
		if (dayIndex>days) break;
		if (i<startWeek)
		{
			printf("   	");
		}else{
			printf("%4d	",dayIndex);
			dayIndex++;
		}
		if (i%7==0) printf("
");
	}
	printf("
");
}
#endif

调用方式如下：

#include <stdio.h>
#include "Date.h"
int main( void )
{	

	printMouth(2013,10);
	
}

运行结果如下：

*********************2013年10月******************************

 Mon     Tue     Wed     Thu     Fri     Sat     Sun
           1       2       3       4       5       6
   7       8       9      10      11      12      13
  14      15      16      17      18      19      20
  21      22      23      24      25      26      27
  28      29      30      31
请按任意键继续. . .