/*
** e2.c
**	programs for exam#2, questions 2, 3, and 4
**   -- written by Jeff Tian, 11/4/99.     
*/

#include <stdio.h>
#include <math.h>
#include <ctype.h>
#include "genlib.h"
#include "simpio.h"
#include "graphics.h"

void pfList(int x);
void ukFlag(float x0, float y0, float width, float height);
void jpFlag(float x0, float y0, float width, float height, float radius);
void pName(void);
void ignoreline(void);

main()
{
   char c;

   printf("Personal Names (E#2, Q#4)\n");
   printf("=========================\n");
   printf("\nContinue with personal names [y/n]? ");
   c = getchar();
   ignoreline();
   while (c == 'y' || c == 'Y')
   {
      printf("Please enter a name: ");
      pName();
      printf("\nContinue with personal names [y/n]? ");
      c = getchar();
      ignoreline();
   }

   printf("\nPrime Factors (E#2, Q#2)\n");
   printf("=========================\n");
   printf("\nContinue with prime factors [y/n]? ");
   c = getchar();
   ignoreline();
   while (c == 'y' || c == 'Y')
   {
      printf("Please enter a positive integer: ");
      pfList(GetInteger());
      printf("\nContinue with prime factors [y/n]? ");
      c = getchar();
      ignoreline();
   }

   printf("\nFlags (E#2, Q#3)\n");
   printf("=========================\n");
   printf("Pause. Press any key to continue.\n");
   getchar();
   InitGraphics();
   ukFlag(1, 1, 3, 2);
   printf("Pause. Press any key to continue.\n");
   getchar();
   InitGraphics();
   jpFlag(1, 1, 3, 2, 0.75);
}

/*
** pfList() -- function for Exam#2, Question 2.
*/ 

void pfList(int x)
{
   int i=2, limit, first=1, unique=1;

   printf("The prime factors for %d are: ", x);
   limit = sqrt(x);
   while (i <= limit )
   {
      if(x%i == 0)
      {
         if(unique)
         {
            unique = 0;
            if(first) 
            {
               printf("<%d", i);
               first = 0;
            }
            else
            {
               printf(", %d", i);
            }
         }
         x = x/i;
         limit = sqrt(x);
      }
      else
      {
         i++;
         unique = 1;
      }
   }
   if(first)
      printf("<%d>\n", x);
   else if(i != x)
      printf(", %d>\n", x);
   else
      printf(">\n");
}

/*
** ukFlag(): function for Exam#2, Question 3 
*/

void
ukFlag(float x0, float y0, float width, float height)
{
   MovePen(x0, y0);
   DrawLine(width, 0);
   DrawLine(0, height);
   DrawLine(-width, 0);
   DrawLine(0, -height);

   DrawLine(width, height);
   MovePen(x0, y0 + height);
   DrawLine(width, - height);

   MovePen(x0 + width/2, y0);
   DrawLine(0, height);
   MovePen(x0, y0 + height/2);
   DrawLine(width, 0);
}


/*
** jpFlag(): function for Exam#2, Question 3 
*/

void
jpFlag(float x0, float y0, float width, float height, float radius)
{
   MovePen(x0, y0);
   DrawLine(width, 0);
   DrawLine(0, height);
   DrawLine(-width, 0);
   DrawLine(0, -height);

   MovePen(x0 + width/2 + radius, y0 + height/2);
   DrawArc(radius, 0, 360);
}

/*
** pName(): function for Exam#2, Question 4.
*/

void pName()
{
   char c;

   if(isupper(c=getchar()))
   {
      while(islower(c=getchar()));
      if (isspace(c))
      {
         if(isupper(c=getchar()))
         {
            while(islower(c=getchar()));
            if (c == '\n')
            {
               printf("Good name.\n");
               return;
            }
         }    
      }
   }

   ignoreline();
   printf("Bad name.\n");
}
         
/*
** ignoreline(): ignore all input until the end of the line
*/

void ignoreline()
{
   while(getchar() != '\n');
}