mohamed saad

 #include<iostream.h>
#include<stdlib.h>

 int main()
{

 int d,m,y,year,month,day,i,n;

 cout<<"Enter the date :";
 cin>>d>>m>>y;
 if( d>31 || m>12 || (y<1900 || y>=2010) )
  {
	cout<<"INVALID INPUT";

	exit(0);
  }
 year = y-1900;
 year = year/4;
 year = year+y-1900;
 switch(m)
  {
	case 1:
	case 10:
			 month = 1;
			 break;
	case 2:
	case 3:
	case 11:
			 month = 4;
			 break;
	case 7:
	case 4:
			month = 0;
			break;
	case 5:
			month = 2;
			break;
	case 6:
			month = 5;
			break;
	case 8:
			month = 3;
			break;
	case 9:
	case 12:
			month = 6;
			break;
  }
 year = year+month;
 year = year+d;
 day  = year%7;
 switch(day)
  {
	case 0:
		cout<<"Day is SATURDAY";
			break;
	case 1:
			cout<<"Day is SUNDAY";
			break;
	case 2:
			cout<<"Day is MONDAY";
			break;
	case 3:
			cout<<"Day is TUESDAY";
			break;
	case 4:
			cout<<"Day is WEDNESDAY";
			break;
   case 5:
		cout<<"Day is THURSDAY";
			break;
   case 6:
		cout<<"Day is FRIDAY";
			break;
  }


 return 0;
}