用C语言计算给定年份中给定日期的总数(即星期日或星期一等)

Question

正如标题所示，我想用c语言计算给定年份范围内1600-2500之间给定日期的总数。我已经编写了一些代码，但仍停留在计算闰年天数上。请帮助我。

#include<stdio.h>
#include<string.h>

int calculateNoOfDays(int year,int choice);
int isLeap(int year);

int main()
{
    int choice,year;    
    int count;
    char dayName[12];

     do{
         printf("Please Enter a year between 1601 and 2500\n");
         scanf("%d",&year);
     }
     while(!(year>=1601 && year<=2500));


 printf("Please select an option between 1 and 7: \nMonday: 1\nTuesday: 2\nWednesday: 3\nThursday: 4\nFriday: 5\nSaturday: 6\nSunday: 7\n");
        scanf("%d",&choice);


    switch((choice))
    {

            case 1:strcpy(dayName,"Monday");
    break;
        case 2:strcpy(dayName,"Tuesday");
    break;
    case 3:strcpy(dayName,"Wednesday");
    break;
    case 4:strcpy(dayName,"Thursday");
    break;
    case 5:strcpy(dayName,"Friday");
    break;
    case 6:strcpy(dayName,"Saturday");
    break;
    case 7:strcpy(dayName,"Sunday");
    break;

}

count=calculateNoOfDays(year,choice);
printf("For the given year, the number of %ss in that year is: %d \n",dayName,count);

return (1);
}

Answer 1

正如您可以阅读的那样 here确定哪些年份是闰年非常容易。这是伪代码:

if year is divisible by 400 then
   is_leap_year
else if year is divisible by 100 then
   not_leap_year
else if year is divisible by 4 then
   is_leap_year
else
   not_leap_year

这样你就得到了一年的天数:365 或 366。

下一步是确定 1 月 1 日是哪一天。这应该可以通过摆弄标准 C date/time library functions 来实现。 。您可能需要进行一些迭代才能达到目标，但如果您足够聪明，也许不需要。

剩下的就是简单的计算即可得到您的天数。