#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
 
int a[10][10]={0};
int b[10][10]={0};
void singleplay(int, int);
void mainmenu();
void newgame();
void loadgame();
 
int main()
{
 mainmenu();
 return 0;
}
 
void mainmenu()
{
	int choice;
	do
	{
    system("cls");
	printf("\t\tSliding Numbers\n\t\tMenu\n\t\t1. Start a new game\n\t\t2. Load a game\n\t\t3. Exit");
    printf("\n\t\t Enter a choice: ");
	scanf("%d", &choice);
	switch (choice)
	{
	 case 1: newgame(); break;
	 case 2: loadgame(); break;
	 case 3: printf("\n\nGoodbye\n"); exit(0);
	 default: printf("\nInvalid Choice\n"); system("PAUSE"); break;
	}
	} while (choice<1 || choice>3);
}
 
void newgame()
{
 int n, holes, noofelements, rowpos, colpos, choice; 
 int i,j;
 srand(time(NULL));
 for(i = 0; i <10; i++)
 {
 	 for(j = 0; j <10; j++)
		 a[i][j] = -1;
 }
 do
 {
  printf("Enter the size of the square (+ve integer, max 257): ");
  scanf("%d", &n);
  if (n<1 || n>256)
	 printf("Invalid size.");
 }
 while (n<1 || n>256);
 do
 {
  printf("Enter the number of holes (max %d): ", n/2);
  scanf("%d", &holes);
  if (holes>(n/2))
 	 printf("Invalid number of holes");
 }
 while (holes>(n/2));
 noofelements=n*n-holes;
   for (i=1; i<=noofelements; i++)
	{
	 do {
	    	rowpos=rand() % n;
			colpos=rand() % n;
		} 
	 while( a[rowpos][colpos] >= 0);
		a[rowpos][colpos]=i;
	}										//do while loop doesnt work here.
	for (i=0; i<n; i++) //display
	{
		for (j=0; j<n; j++)
		{
		    if (a[i][j]==-1)
			 printf("%c", ' ');
			else
			printf("%d\t", a[i][j]);
		}
		printf("\n");
	}
 singleplay(n, holes);
}
 
void loadgame()
{
 int i,j,matricsize,spaces;
 char choice; 
 FILE *infile;
 char filename[13];
 char quit[]="quit";
 do
 {
  printf("\n\n Please enter a filename (xxxxxxxx.yyy) or 'quit' to exit: ");
  scanf("%s", filename);
  if (strcmp(filename, quit)==0) 
	 mainmenu();
  else
  if ((infile = fopen(filename, "r")) == NULL)  
     printf("\n Filename invalid");
 }
 while (((infile = fopen(filename, "r")) == NULL));  
 fscanf(infile,"%d", &matricsize);
 fscanf(infile,"%d", &spaces);
 for(i=0;i<matricsize;i++)
  for(j=0;j<matricsize;j++)
   fscanf(infile,"%d", &a[i][j]);
 fclose(infile);
 for (i=0;i<matricsize;i++)		//display
 {
  printf("\n");
  for (j=0;j<matricsize;j++)
  {
   printf("\t%d",a[i][j]);
  }
 }
 printf("\n\n\n");
 do					//doesnt work but system("cls") covers it up
 {
  printf("\nThe above data will be loaded. do u want to continue? (y/n): ");
  scanf("%ch",&choice);
  switch (choice)
  {
   case 'y': singleplay(matricsize, spaces); break;
   case 'Y': singleplay(matricsize, spaces); break;
   case 'n': mainmenu(); break;
   case 'N': mainmenu(); break;
   default: printf("Invalid choice\n"); break;
  }
 }
 while (choice!='y' && choice!='Y' && choice!='n' && choice!='N');
}
 
void singleplay(int n, int holes)
{
 int i, j, k=0, noofelements, correct=0, temp;
 int x1, y1, x2, y2;
 system("cls");
 for (i=0; i<n; i++)  //display with coordinates
	 printf("\t%d", (i));
 printf("\n\n");
 for (i=0; i<n; i++)
 {
  printf("%d\t", (i));
  for (j=0; j<n; j++)
  {
   if (a[i][j]==-1)
   printf(" ");
   else
   printf("%d\t", a[i][j]);
  }
  printf("\n");
 }
 noofelements=n*n-holes;
 for (i=0; i<n; i++)
	 for(j=0; j<n; j++)
	 {
		 if (k<noofelements)
		 {
		 k++;
		 b[i][j]=k;
		 }
	 }
 while (correct==0) //swapping
 {
  printf("Enter the x y coordinates of the element to be moved: ");
  scanf("%d %d", &x1, &y1);
  y1++;
  if (x1>=n || y1>=n)
	  printf("\nInvalid coordinate\n");
  printf("Enter the x y coordinates of the empty space: ");
  scanf("%d %d", &x2, &y2);
  y2+=2;
  if (x2>=n || y2>=n)
	  printf("\nInvalid coordinate\n");
  temp=a[x1][y1];
  //testing:
  printf("\n%d\n", a[x1][y1]);
  a[x1][y1]=a[x2][y2];
  //testing:
  a[x2][y2]=temp;
  printf("\n%d\n", temp);
 
  for (i=0; i<n; i++) //display with coordinates
	 printf("\t%d", (i));
     printf("\n\n");
  for (i=0; i<n; i++)
  {
   printf("%d\t", (i));
   for (j=0; j<n; j++)
   {
    if (a[i][j]==-1)
    printf(" ");
    else
    printf("%d\t", a[i][j]);
   }
   printf("\n");
  }
  for (i=0; i<n; i++)  //checking if matrix has been solved
	 for (j=0; j<n; j++)
	 {
	  if (a[i][j]!=b[i][j])
	  {correct=0; break;}
	  else
	  correct=1;
	 }
 }
}