该程序简单地输入一个年份（1901年之后的年份），随后程序输出该年份十二个月的日历。
#include<stdio.h>
#define Mon 1
#define Tues 2
#define Wed 3
#define Thur 4
#define Fri 5
#define Sat 6
#define Sun 0
#define January_days 31
#define February_days 28
#define March_days 31
#define April_days 30
#define May_days 31
#define June_days 30
#define July_days 31
#define August_days 31
#define September_days 30
#define October_days 31
#define November_days 30
#define December_days 31
#define first1month January_days
#define first2month January_days+February_days
#define first3month January_days+February_days+March_days
#define first4month January_days+February_days+March_days+April_days
#define first5month January_days+February_days+March_days+April_days+May_days
#define first6month January_days+February_days+March_days+April_days+May_days+June_days
#define first7month January_days+February_days+March_days+April_days+May_days+June_days \
+July_days
#define first8month January_days+February_days+March_days+April_days+May_days+June_days \
+July_days+August_days
#define first9month January_days+February_days+March_days+April_days+May_days+June_days \
+July_days+August_days+September_days
#define first10month January_days+February_days+March_days+April_days+May_days+June_days \
+July_days+August_days+September_days+October_days
#define first11month January_days+February_days+March_days+April_days+May_days+June_days \
+July_days+August_days+September_days+October_days+November_days
int known_weekday = Tues;
int known_year = 1901;
int konwn_month = 1;
int known_day = 1;
int day_count(int month)
{
switch(month)
{
case 1: return 0;break;
case 2: return first1month;break;
case 3: return first2month;break;
case 4: return first3month;break;
case 5: return first4month;break;
case 6: return first5month;break;
case 7: return first6month;break;
case 8: return first7month;break;
case 9: return first8month;break;
case 10: return first9month;break;
case 11: return first10month;break;
case 12: return first11month;break;
}
}
/*char * month_name(int month)
{
switch(month)
{
case 1:
return "January";
break;
case 2:
return "February";
break;
case 3:
return "March";
break;
case 4:
return "April";
break;
case 5:
return "May";
break;
case 6:
return "June";
break;
case 7:
return "July";
break;
case 8:
return "August";
break;
case 9:
return "September";
break;
case 10:
return "October";
break;
case 11:
return "November";
break;
case 12:
return "December";
break;
default:
break;
}
}*/
char * month_name(int month)
{
switch(month)
{
case 1:
return "一月";
break;
case 2:
return "二月";
break;
case 3:
return "三月";
break;
case 4:
return "四月";
break;
case 5:
return "五月";
break;
case 6:
return "六月";
break;
case 7:
return "七月";
break;
case 8:
return "八月";
break;
case 9:
return "九月";
break;
case 10:
return "十月";
break;
case 11:
return "十一月";
break;
case 12:
return "十二月";
break;
default:
break;
}
}
/*按格式打印某年某月名称*/
void first_line_print(int month, int year)
{
//printf("%20s %d \n",month_name(month),year);
printf("%8d年 %s \n",year, month_name(month));
}
/*按格式打印星期名称*/
void week_print()
{
//printf("%-6s%-6s%-6s%-6s%-6s%-6s%-6s\n","Sun.", "Mon.", "Tues.", "Wed.", "Thur.", "Fri.", "Sat.");
printf("%-3s%-3s%-3s%-3s%-3s%-3s%-3s\n","日", "一", "二", "三", "四", "五", "六");
}
/*计算该年该月份与已知日子之间的距离天数*/
int date_distance_count(int month, int year)
{
int leap_year_count = 0;
int i;
int distance;
if (year > known_year)
{
for (i=known_year; i<year; i++)
{
if(((i%4 == 0) && (i%100 != 0) ) || (i%400 == 0))
{
leap_year_count++;
}
}
if (month > 2)
{
if(((year%4 == 0) && (year%100 != 0) ) || (year%400 == 0))
{
leap_year_count++;
}
}
}
else
if (year == known_year)
{
if (month > 2)
{
leap_year_count = 1;
}
}
distance = (year - known_year)*365 + leap_year_count + day_count(month);
return distance;
}
/*确定该月份第一天是星期几*/
int makesure_firstday_weekday(int month, int year)
{
int date_distance = 0;
int weekday;
date_distance = date_distance_count(month, year);
weekday = (known_weekday + date_distance)%7;
return weekday;
}
/*依次打印出该月份的日子*/
void print_in_turn(int month, int firstday, int year)
{
int i = 1;
int weekday;
switch(firstday)
{
case Sun:
break;
case Mon:
printf("%-3s","");
break;
case Tues:
printf("%-6s","");
break;
case Wed:
printf("%-9s","");
break;
case Thur:
printf("%-12s","");
break;
case Fri:
printf("%-15s","");
break;
case Sat:
printf("%-18s","");
break;
}
switch(month)
{
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
{
for(i=0; i<31; i++)
{
weekday = (firstday + i)%7;
printf("%-3d",i+1);
if(weekday == Sat)
{
printf("\n");
}
}
break;
}
case 2:
{
if(((year%4 == 0) && (year%100 != 0) ) || (year%400 == 0)) /*闰年*/
{
for(i=0; i<29; i++)
{
weekday = (firstday + i)%7;
printf("%-3d",i+1);
if(weekday == Sat)
{
printf("\n");
}
}
break;
}
else /*平年*/
{
for(i=0; i<28; i++)
{
weekday = (firstday + i)%7;
printf("%-3d",i+1);
if(weekday == Sat)
{
printf("\n");
}
}
break;
}
}
case 4:
case 6:
case 9:
case 11:
{
for(i=0; i<30; i++)
{
weekday = (firstday + i)%7;/*计算该天是星期几*/
printf("%-3d",i+1);
if(weekday == Sat)
{
printf("\n");/*如果是星期六，则换行*/
}
}
break;
}
}
}
void date_print(int month, int year)
{
int firstday;
firstday = makesure_firstday_weekday(month, year);
print_in_turn(month, firstday, year);
printf("\n");
}
void main_month(int month, int year)
{
first_line_print(month, year);
week_print();
date_print(month, year);
printf("\n\n");
}
void main_calendar(int year)
{
int i;
for(i=1; i<=12; i++)
{
main_month(i, year);
}
}
int main()
{
int year;
printf("请输入年份：year = ");
scanf("%d",&year);
printf("\n");
while(year < 1902)
{
printf("请输入大于1901的年份\n");
printf("请输入年份：year = ");
scanf("%d",&year);
printf("\n");
}
main_calendar(year);
scanf(" ");
return 0;
}
运行效果图：