第十二周项目1-求某年某月是本年的第几天

#include <iostream>
using namespace std;
int time(int,int,int);
int main( )
{
	int year,month,day,z;
	cout<<"请依次输入年、月、日:"<<endl;
	cin>>year>>month>>day;
	z=time(year,month,day);
	cout<<year<<"年"<<month<<"月"<<day<<"日是第"<<z<<"天"<<endl;
	return 0;
}
int time(int year,int month,int day) 
{
	int z,a;
	if(year%4==0&&year%100!=0||year%400==0)
	{
		a=29;
		
	}else
		a=28; 
	switch(month)
	{
	case 1:z=day;break;
	case 2:z=31+day;break;
	case 3:z=31+a+day;break;
	case 4:z=31*2+a+day;break;
	case 5:z=2*31+30+a+day;break;
	case 6:z=3*31+30+a+day;break;
         case 7:z=31*3+30*2+a+day;break;   
         case 8:z=31*4+30*2+a+day;break;
         case 9:z=31*5+30*2+a+day;break;
         case 10:z=5*31+30*3+a+day;break;
	case 11:z=6*31+30*3+a+day;break;
	case 12:z=6*31+30*4+a+day;break;
	}
	
	
	return z;
}

运行结果：

心得体会：善于运用各种工具能使程序看起来简洁明了~