凱撒日期

所謂的凱撒日期就是輸入一個日期輸出這一天是這一年中的第幾天。

這是今天在論壇幫人寫的一個小程序，好久沒寫c了，寫個簡單的練練，記錄下。

#include <stdio.h>
#include <stdbool.h>
int main(){
    int year;    //the year
    int mon;    //the month
    int day;    //the day
    int dayOfYear = 0;   //day of the year
    bool leapYear;   //if the year is a leap year??

      printf("Please enter the data(YYYY-MM-DD): ");
      scanf("%d-%d-%d",&year,&mon,&day);
      while((mon < 1 || mon > 12)||(day < 0 || day > 31)){   //check the input
            printf("Enter error!Please enter again!\n\n");
            printf("Please enter the data(YYYY-MM-DD): ");
            scanf("%d-%d-%d",&year,&mon,&day);
      }



    if((year % 4 == 0 && year % 100 != 0)||(year % 400 == 0)){//if the year is a leap year,then leapYear=true
        leapYear = true;
    }
    else{
        leapYear = false;
    }


    if(leapYear){   //if the year is a leap year
        if(mon == 1){
            dayOfYear == day;
        }
        else if(mon == 2){
            dayOfYear = 31 + day;
        }
        else if(mon > 2) {
            dayOfYear += 60;
            dayOfYear += day;
            for(int i = 3;i< mon;i++){
                if((i == 1)||(i == 3)||(i == 5)||(i == 7)||(i == 8)||(i == 10)||(i == 12)){
                  dayOfYear += 31;
                  }
                else if((i == 4)||(i == 6)||(i == 9)||(i == 11)){
                    dayOfYear += 30;
                }
          }

        }

    }

    else if(!leapYear){//if the year is not a leap year
        if(mon == 1){
            dayOfYear == day;
        }
        else if(mon == 2){
            dayOfYear = 31 + day;
        }
        else if(mon > 2) {
            dayOfYear += 59;
            dayOfYear += day;
            for(int i = 3;i< mon;i++){
                if((i == 1)||(i == 3)||(i == 5)||(i == 7)||(i == 8)||(i == 10)||(i == 12)){
                  dayOfYear += 31;
                  }
                else if((i == 4)||(i == 6)||(i == 9)||(i == 11)){
                    dayOfYear += 30;
                }
          }

        }
    }

    printf("The day of the year is: %d\n",dayOfYear);
}