C语言实现万年历

一、项目介绍

需求和功能是用纯C语言实现一个可以属于年份，属于一个年份就可以显示该年各个月份的日历，如同日历一般，每个月当中每天对应的星期均可查看，即万年历，要求格式整齐，星期对照直观。

二、运行截图

三、完整源码

#include<stdio.h>
#include<windows.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;
    }
}
  
const 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;
}