使用枚举的日历

Question

我正在尝试在枚举的帮助下编写一个程序，我可以用它来显示今天和第二天。问题是我不知道如何从键盘输入今天来计算第二天。如果我在代码中输入变量，它会正确计算。我正在尝试学习 C，但我仍处于起步阶段，这就是为什么我使用了一些不必要的功能。

#include <stdio.h>
#include <stdlib.h>


typedef enum {jan, feb, mar, apr, may, jun, jul, aug, sep, oct, nov, dec} month;


int day_today(month m, int i)
{
    int day_of_month;
    switch (m)
    {
        case jan: printf("january %d \n", i);
                  day_of_month = 31;
                  break;
        case feb: printf("february %d \n", i);
                  day_of_month = 28;
                  break;
        case mar: printf("march %d \n", i);
                  day_of_month = 31;
                  break;
        case apr: printf("april %d \n", i);
                  day_of_month = 30;
                  break;
        case may: printf("may %d \n", i);
                  day_of_month = 31;
                  break;
        case jun: printf("june %d \n", i);
                  day_of_month = 30;
                  break;
        case jul: printf("jule %d \n", i);
                  day_of_month = 31;
                  break;
        case aug: printf("august %d \n", i);
                  day_of_month = 31;
                  break;
        case sep: printf("september %d \n", i);
                  day_of_month = 30;
                  break;
        case oct: printf("pctomber %d \n", i);
                  day_of_month = 31;
                  break;
        case nov: printf("november %d \n", i);
                  day_of_month = 30;
                  break;
        case dec: printf("december %d \n", i);
                  day_of_month = 31;
                  break;
        default: printf("Error at input month \n");
    }
    return day_of_month;
}

month next_month(month m)
{
        return(m+1%12);
}

int next_day(int d)
{
    return(d+1);
}

int main()
{
    month a_month = feb ;
    int d = 28 ;
    int day_of_month;
    //printf("Give the month and day: ");
    //scanf("%c %d\n", &a_month, &d);
    day_of_month = day_today(a_month, d);
    if (d >= day_of_month)
        {
            a_month = next_month(a_month);
            d = 1;
        }
    else d = next_day(d);
    printf( day_today(a_month,d));

    return 0;
}

Answer 1

你的scanf有误，试试：

scanf("%d", &a_month);

Answer 2

同时添加对用户日期输入的错误检查。它必须在 [1,max_day_of_month] 之内。如果不进行此项检查，则不应打印当前日期。

这是检查输入日期的实现之一。

#include <stdio.h>
#include <stdlib.h>


typedef enum {jan, feb, mar, apr, may, jun, jul, aug, sep, oct, nov, dec} month;

void isValidDate(int day_of_month,int d, char* s)
{
    if(d>=1 && d<=day_of_month)
        printf("%s %d\n",s,d);
}

int day_today(month m, int i)
{
    int day_of_month;
    switch (m)
    {
        case jan: day_of_month = 31; 
                  isValidDate(day_of_month,i,"january");
                  break;
        case feb: day_of_month = 28;
                  isValidDate(day_of_month,i,"february");
                  break;
        case mar: day_of_month = 31;
                  isValidDate(day_of_month,i,"march");
                  break;
        case apr: day_of_month = 30;
                  isValidDate(day_of_month,i,"april");
                  break;
        case may: day_of_month = 31;
                  isValidDate(day_of_month,i,"may");
                  break;
        case jun: day_of_month = 30;
                  isValidDate(day_of_month,i,"june");
                  break;
        case jul: day_of_month = 31;
                  isValidDate(day_of_month,i,"july");
                  break;
        case aug: day_of_month = 31;
                  isValidDate(day_of_month,i,"august");
                  break;
        case sep: day_of_month = 30;
                  isValidDate(day_of_month,i,"september");
                  break;
        case oct: day_of_month = 31;
                  isValidDate(day_of_month,i,"octomber");
                  break;
        case nov: day_of_month = 30;
                  isValidDate(day_of_month,i,"november");
                  break;
        case dec: day_of_month = 31;
                  isValidDate(day_of_month,i,"december");
                  break;
        default: printf("Error at input month \n");
    }
    return day_of_month;
}

month next_month(month m)
{
        return((m+1)%12);
}

int next_day(int d)
{
    return(d+1);
}

int main()
{
    month a_month = 1 ;
    int d = 28 ;
    
    printf("Give the month and day: ");
    scanf("%u %d", &a_month, &d);
    int day_of_month = day_today(a_month, d);
    if (d > day_of_month)
    {
        fprintf(stderr,"Invalid Date");
        return -1;
    }
    else if(d == day_of_month)
    {
        a_month = next_month(a_month);
        d = 1;
    }
    else
        d = next_day(d);

    printf("Next, a_month = %d, d = %d\n",a_month,d);

    return 0;
}

使用枚举的日历

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