USACO:Section 1.1 Friday the Thirteenth

/*
ID:lwj13961 
TASK:friday
LANG: C++
*/

#include<iostream>
#include<fstream>
#include<cassert>
using namespace std;

bool isleapyear(int year)
{
	if(year%100!=0&&year%4==0) return true;
	if(year%100==0&&year%400==0) return true;
	return false;
}

int main()
{
	int N;
	int fre[7]={0};
	int normalyear[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
	int leapyear[12] = {31,29,31,30,31,30,31,31,30,31,30,31};
    int *pyear; 	
	int days=0;

	//////////////////////////////////////get input 
	char *ifs_file_name = "friday.in";		/* input  file name       */
	ifstream	ifs;							/* create ifstream object */

	ifs.open (ifs_file_name);		/* open ifstream          */
	if (!ifs) {
		cerr << "\nERROR : failed to open input  file " << ifs_file_name << endl;
		exit (EXIT_FAILURE);
	}
	ifs>>N;
	assert(N>=0&&N<=400);
	ifs.close ();		/* close ifstream         */
	//////////////////////////////////////
	

	for(int i=0;i<N;i++)
	{
		if(isleapyear(1900+i))
		{
			pyear=leapyear;
			cout<<1900+i<<" 闰年 "; 
		}
		else
			pyear=normalyear;

		for(int j=0;j<12;j++)
		{
			int t;
			if(j>0)
			{
				days += pyear[j-1];
				t=(days+13)%7;
			}
			else
			{
				if(i>0)
					days += 31;
				t=(days+13)%7;
			}
			fre[t]++;
			//cout<<1900+i<<"年 "<<j+1<<" 月13号是星期"<<t<<endl;
		}	
	}


	//////////////////////////////////////make ouput
	
	char *ofs_file_name = "friday.out";		/* output file name       */
	ofstream	ofs;							/* create ofstream object */

	ofs.open (ofs_file_name);		/* open ofstream          */
	if (!ofs) {
		cerr << "\nERROR : failed to open output file " << ofs_file_name << endl;
		exit (EXIT_FAILURE);
	}

	ofs<<fre[6];
	for(int i=0;i<6;i++)
		ofs<<" "<<fre[i]; 
	ofs<<endl;
	ofs.close ();		/* close ofstream         */
	//////////////////////////////////////

	getchar();getchar();
	return 0;
}