這次代碼的編寫讓我意識(shí)到自己的歸納總結(jié)能力實(shí)在是太差了。

個(gè)人代碼

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

void tomorrow(int *y, int *m, int *d)
{
    //判斷30和31號(hào),沒有2月 
    if(*d > 29)
    {
        //小月的30號(hào) 
        if(*m == 4 || *m == 6 || *m == 9 || *m == 11)
        {
            *m += 1;
            *d = 1;
        }
        //大月的30號(hào) 
        else
        {
            *d += 1;
        } 
        
        //31號(hào) 
        if(*d == 31)
        {
            //12月31號(hào) 
            if(*m == 12)
            {
                *y += 1;
                *m = 1;
                *d = 1;
            }
            //其他大月 
            else
            {
                *m += 1;
                *d = 1;
            }
         } 
    }
    //1~29號(hào)友多，判斷閏昧捷、平年 
    else
    {
        //閏年
        if((*y % 4 == 0 && *y % 100 != 0) || *y % 400 == 0)
        {
            if(*d == 29)
            {
                *m += 1;
                *d = 1;
            }
            else
            {
                *d += 1;
            }
        }
        //平年
        else if(*d == 28)
        {
            *m += 1;
            *d = 1;
        } 
        else
        {
            *d += 1;
        }
    }
}

void yesterday(int *y, int *m, int *d)
{
    //大于1號(hào) 
    if(*d > 1)
    {
        *d -= 1;
    }
    //1號(hào) 
    else
    {
        //大于1月 
        if(*m > 1)
        {
            *m -= 1;
            //2月
            if(*m == 2)
            {
                //閏年 
                if((*y % 4 == 0 && *y % 100 != 0) || *y % 400 == 0)
                {
                    *d = 29;
                }
                //平年 
                else
                {
                    *d = 28;
                }
            }
            
            //小月
            if(*m == 4 || *m == 6 || *m == 9 || *m == 11)
            {
                *d == 30;
            }
            //大月 
            else
            {
                *d == 31;
            }
        }
        //1月 
        else
        {
            *y -= 1;
            *m = 12;
            *d = 31;
        }
    }
}

int main()
{
    int y, m, d;
    
    scanf("%d %d %d", &y, &m, &d);
    
    yesterday(&y, &m, &d);
    printf("前一天：%d年%d月%d日\(chéng)n", y, m, d);
    
//  tomorrow(&y, &m, &d);
//  printf("后一天：%d年%d月%d日\(chéng)n", y, m, d);
    
    system("pause");
    return (0); 
}

歸納后的代碼

出處：http://blog.csdn.net/cloudmonke/article/details/53783682

#include <stdio.h>  
  
// 判斷閏年  
int is_leap(int year)  
{  
    int i = 0;  
      
    if (((year % 4) == 0 && (year % 100) != 0) || (year % 400 == 0))  
        i = 1;  
    return (i);  
}  
  
// 返回當(dāng)月天數(shù)  
int days(int year, int month)  
{  
    int i;  
      
    switch (month) {  
        case 4:  
        case 6:  
        case 9:  
        case 11: i = 30; break;   
        case 2: if (is_leap(year)) i = 29; else i = 28; break;  
        default: i = 31; break;  
    }  
    return (i);  
}  
   
// 求出前一天  
void yesterday(int *y, int *m, int *d)  
{     
    (*d)--;  
      
    if (!(*d)) {  
        (*d) = days(*y, --(*m));  
    }  
      
    if (!(*m)) {  
        (*y)--;  
        (*m) = 12;   
    }     
}   
  
// 求出后一天  
void tomorrow(int *y, int *m, int *d)  
{  
    (*d)++;  
      
    if ((*d) > days(*y, *m)) {  
        (*d) = 1;  
        (*m)++;         
    }  
      
    if ((*m) > 12) {  
        (*y)++;  
        (*m) = 1;  
    }   
           
}  
  
int main(void)  
{  
    int year, month, day;  
    printf("請(qǐng)輸入年月日: ");  
    scanf("%d%d%d", &year, &month, &day);  
    putchar('\n');  
      
    yesterday(&year, &month, &day);  
    printf("前一天：%d %2d %2d\n", year, month, day);  
    tomorrow(&year, &month, &day);  
    printf("輸入日：%d %2d %2d\n", year, month, day);  
    tomorrow(&year, &month, &day);  
    printf("后一天：%d %2d %2d\n", year, month, day);  
      
    return (0);   
}