1. Enter a certain year, month, and day, and determine which day is the day of the year?
Program analysis: Take March 5th as an example, you should first add up the previous two months, and then add 5 days, which is the first day of the year. In special cases, if it is a leap year and the input month is greater than 3, you need to consider adding an extra day .
Input
Please enter the year, month, and day in the format: year, month, and day (2015 12 10)
Output
This is the nth day of the year.
#include<stdio.h>
int addOne ( int year) {
if (year % 4 ==