C Calculate how many days of the 21st century it is?

I specified the end date in the program, and if necessary, you can read it in with the command line, very easy

#include

using namespace std;

int main()

int a=;The cumulative number of days in the month.

int year, month, day;

cin>>year>>month>>day;

*Calculation of the number of days in the current year***

int days = a[month-1] +day;The number of days in the current year.

if((month> whether the current year is a Swiss year.

days++;

*The year of the middle difference is actually calculated ***

int temp = year - 2000;The year in the middle of the difference.

days += 365 * temp;

for(int i=2000; icoutreturn 0;

case 1: case 2:……It should be in this form, month is an integer not a character, and there is no need to add ''

It's not simple, make a two-dimensional array a[2][12] to store months, a[0] to store common years, and a[0] to store leap years! Just add it up with the for loop!

#include

using namespace std;

const int a[13]=;

int n,y,t,sum;

int main()

sum+=t;

if ((n%4==0) &n%100!=0)) n%400==0))

sum+=1;

printf("This day is the %d day of the year. ",sum);

system("pause");

return 0;

Notepad written, no input time error maintenance, hope it helps - Mianzhong oi13 level.

You can use datetime to get the complex.

That is, the current date system is the first day of the year, for example, 2012-02-20 now shows the 51st day of 2012.

If there's a character, that's it.

string str = "2012/02/20 12:00:00";

It's the same way.

Leave a space after the keyword case Ha:

#include

using namespace std;

void main()

cout <<"For the first of the year" <

You're not wrong with me, there's nothing wrong with this, I've run it.

Operating environment GCC

#include

using namespace std;

main()

In the case of leap years, then March and later months are calculated with +1 (28 days in February and 29 days in leap years).

cout<

#include

#include

int main()

if (look)

day1 += day + 1;

elseday1 += day;

printf("%d year, %d month, %d day is the %d day of the year", year, month, day, day1);

system("pause");

return 0;}

if(The problem is here.)

In C++, the comparison operator should be "==" instead of "=".

It is recommended to write if(1== next time, so that if something goes wrong, the compiler will report an error.

Hope it helps!!

#include

using namespace std;

int main()

int a[12]=;

int year,month,day;

int sum=0;

cout<<"Please enter the year, month and day">year>>month>>day;

if(month==1)

sum=day;

else if(month<=2)

sum=31+day;

elseif(year%100==0)

if(year%4==0)

for(int i=0;isum=sum+a[i];

sum=sum+1+day;

elsefor(int k=0;ksum=sum+a[k];

sum=sum+day;

elseif(year%4==0)

for(int i=0;isum=sum+a[i];

sum=sum+1+day;

elsefor(int k=0;ksum=sum+a[k];

sum=sum+day;

cout<<>

The watchtower owner.

#include

void main()

cout<<"Please enter your year, month, and day:"cin>>year>>month>>day;

for(int i=0;i2)

cout<<"This day is the first day of the year"

for (i=0;i The day above has been added many times.