C语言 万年历程序

原代码：

chunli@Linux:~/c++$ cat 123.c #include
     
       #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 "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("%-4s%-4s%-4s%-4s%-4s%-4s%-4s\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
      
        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);    return 0;}chunli@Linux:~/c++$
      
     

编译运行：

chunli@Linux:~/c++$ gcc 123.c  && ./a.out 请输入年份：year = 2016    2016年 一月 日 一 二 三 四 五 六                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     2016年 二月 日 一 二 三 四 五 六    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     2016年 三月 日 一 二 三 四 五 六       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     2016年 四月 日 一 二 三 四 五 六                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     2016年 五月 日 一 二 三 四 五 六 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     2016年 六月 日 一 二 三 四 五 六          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     2016年 七月 日 一 二 三 四 五 六                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     2016年 八月 日 一 二 三 四 五 六    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     2016年 九月 日 一 二 三 四 五 六             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     2016年 十月 日 一 二 三 四 五 六                   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     2016年 十一月 日 一 二 三 四 五 六       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     2016年 十二月 日 一 二 三 四 五 六             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 chunli@Linux:~/c++$