Friday, March 16, 2012

2) Maze: Generating Maze Randomly and Maze Traversal

My version of random maze generator and maze traversal.
This program used Depth First Search Algorithm to generate random maze according to the size input by user, then this program used the Right Hand Wall algorithm for the traversal.
Source:
Depth First Search Algorithm - http://www.mazeworks.com/mazegen/mazetut/index.htm
The recursive version of the maze generator can be found here - http://azerdark.wordpress.com/2009/03/29/588/
/*
 *   Title: Pointers 723 : Generating Maze Randomly & Maze Traverse
 *   Author: aeriqusyairi
 *   Date: Mac5 2012
 *   Algorithm: Depth First Search
 *   
 *      create a CellStack (LIFO) to hold a list of cell locations
 *      set TotalCells = number of cells in grid
 *      choose a cell at random and call it CurrentCell
 *      set VisitedCells = 1 
 *
 *      while VisitedCells < TotalCells 
 *
 *         find all neighbors of CurrentCell with all walls intact
 *         if one or more found
 *            choose one at random
 *            knock down the wall between it and CurrentCell
 *            push CurrentCell location on the CellStack
 *            make the new cell CurrentCell
 *            add 1 to VisitedCells 
 *         else
 *            pop the most recent cell entry off the CellStack
 *            make it CurrentCell 
 *         endIf 
 *
 *      endWhile
 */
#include<stdio.h>
#include<stdlib.h>
#include<time.h>

#define MAX 101 //maxRow + maxColumn + 1
#define WALL 1 //indicate the wall is up
#define PATH 0 //indicate the cells is previous path
#define CELLS 2500 //row * column
#define START 3 //start position
#define END 4 //end position
 
void mazeGenerator( int wMaze[ MAX ][ MAX ], int wSize ); //generate the maze
void startEnd( int wMaze[ MAX ][ MAX ], int wSize, int* wSRow, int* wSCol );//generate start and end position
int mazeTraverse( int maze[ MAX ][ MAX ], int currentRow, int currentColumn, int size );//Automatic maze solver
void printMaze( int wMaze[ MAX ][ MAX ], int wSize );//display the maze
 
int main(void){
   
   int size = 3, sRow = 0, sCol = 0, state;
   int maze[ MAX ][ MAX ]; //maze array 
   
   printf("My Maze Generator\n*****************\n\n");
   printf("Input the size of your desired maze (3 to 50): ");
   do{
      if(size < 3 || size > 50)
         printf("Invalid size! Input again: ");
            
      scanf("%d", &size );//get the desired size from user
   }while(size < 3 || size > 50);
   
   mazeGenerator( maze, size );
   startEnd( maze, size, &sRow, &sCol );
   printMaze( maze, size );
   state = mazeTraverse( maze, sRow, sCol, size );
   
   if(state == 0)
      printf("Player found the exit\n\n");
    
   system("pause");
   return 0;
}
//////////////////
//MAZE GENERATOR//
//////////////////
void mazeGenerator( int wMaze[ MAX ][ MAX ], int wSize ){
   
   srand(time( 0 ));
   
   void initMaze( int wMaze[ MAX ][ MAX ] ); //initalize the maze array
   int walled( int wMaze[ MAX ][ MAX ], int wRow, int wCol );//check neighbouring cells
   
   initMaze( wMaze );
   
   int counter = 0, row = 1, col = 1, visited = 1;
   int validNeighbour, valid, randValid, move;
   int neighbourRow[ 4 ];
   int neighbourCol[ 4 ];
   int step[ 4 ];
   int btRow[ CELLS ]; //backtrack row array
   int btCol[ CELLS ];//backtrack column array
   
   //start backtracking with first cell
   btRow[ 0 ] = 1;
   btCol[ 0 ] = 1;
      
   /*while VisitedCells < TotalCells*/
   while(visited < wSize * wSize){
      //initialize
      validNeighbour = -1;
      
      /*find all neighbors of CurrentCell with all walls intact*/
      //NORTH neighbour
      if(row - 2 > 0 && walled( wMaze, row - 2, col )){
         validNeighbour++;
         neighbourRow[ validNeighbour ] = row - 2;
         neighbourCol[ validNeighbour ] = col;
         step[ validNeighbour ] = 1;       
      } 
      //WEST neighbour
      if(col - 2 > 0 && walled( wMaze, row, col - 2 )){
         validNeighbour++;
         neighbourRow[ validNeighbour ] = row;
         neighbourCol[ validNeighbour ] = col - 2;
         step[ validNeighbour ] = 2;         
      }
      //EAST neighbour
      if(col + 2 < wSize * 2 + 1 && walled( wMaze, row, col + 2 )){
         validNeighbour++;
         neighbourRow[ validNeighbour ] = row;
         neighbourCol[ validNeighbour ] = col + 2;
         step[ validNeighbour ] = 3;         
      } 
      //SOUTH neighbour
      //size * 2 + 1 -> size + wall + outerWall
      if(row + 2 < wSize * 2 + 1 && walled( wMaze, row + 2, col )){
         validNeighbour++;
         neighbourRow[ validNeighbour ] = row + 2;
         neighbourCol[ validNeighbour ] = col;
         step[ validNeighbour ] = 4;         
      }
      
      //if one or more found
      if(validNeighbour != -1){
         //choose one at random
         valid = validNeighbour + 1;//number of valid neighbour
         randValid = rand() % valid;
         
         //make the new cell CurrentCell
         row = neighbourRow[ randValid ];
         col = neighbourCol[ randValid ];
         
         counter++;
         
         btRow[ counter ] = row;
         btCol[ counter ] = col;
         
         move = step[ randValid ];
         
         //knock down the wall between it and CurrentCell
         //NORTH
         if(move == 1){
            wMaze[ row + 1 ][ col ] = PATH;        
         }
         //WEST
         else if(move == 2){
            wMaze[ row ][ col + 1 ] = PATH;     
         }
         //EAST
         else if(move == 3){
            wMaze[ row ][ col - 1 ] = PATH;     
         }
         //SOUTH
         else if(move == 4){
            wMaze[ row - 1 ][ col ] = PATH;     
         }
         
         //add 1 to VisitedCells
         visited++;
      }
      //if none found 
      else{
         //backtracking
         row = btRow[ counter ];
         col = btCol[ counter ];
         counter--;      
      }
       
   }                           
}

void initMaze( int wMaze[ MAX ][ MAX ] ){
   int a, b;
   
   for(a  = 0; a < MAX; a++){
      for(b = 0; b < MAX; b++){
         if(a % 2 == 0 || b % 2 == 0){
            wMaze[ a ][ b ] = WALL;   
         }else{
            wMaze[ a ][ b ] = PATH;      
         }
      }       
   }     
}

void printMaze( int wMaze[ MAX ][ MAX ], int wSize ){
   int row, col;
   
   printf("\n");
   
   for(row = 0; row < wSize * 2 + 1; row++){
           
      if(wMaze[ row ][ 0 ] == START)
         printf(" START -> ");
      else
         printf("          ");
         
      for(col = 0; col < wSize * 2 + 1; col++){
         if(wMaze[ row ][ col ] == WALL)
            printf("#");
         else if(wMaze[ row ][ col ] == START)
            printf("X");
         else
            printf(" ");        
      } 
      
      if(wMaze[ row ][ wSize * 2 ] == END)
         printf(" <- END");
                
      printf("\n");
   }  
   printf("\n"); 
   system("pause");
   system("cls");     
}

int walled( int wMaze[ MAX ][ MAX ], int wRow, int wCol ){
   if(wMaze[ wRow - 1 ][ wCol ] == WALL &&
      wMaze[ wRow + 1 ][ wCol ] == WALL &&
      wMaze[ wRow ][ wCol + 1 ] == WALL &&
      wMaze[ wRow ][ wCol - 1 ] == WALL )
      return 1;
      
   return 0;    
}
////////////////////////////////////
//START AND END POSITION GENERATOR//
////////////////////////////////////
void startEnd( int wMaze[ MAX ][ MAX ], int wSize, int* wSRow, int* wSCol ){
   int start, end;
   
   do{
      start = rand() % (wSize * 2);//size + wall
   }while(start == 0 || wMaze[ start ][ 1 ] == WALL );
          
   do{
      end = rand() % (wSize * 2);   
   }while(end == 0 || wMaze[ end ][ (wSize * 2) - 1 ] == WALL);  
   
   wMaze[ start ][ 0 ] =  START;
   wMaze[ end ][ wSize * 2 ] = END; 
   
   *wSRow = start;
   *wSCol = 0; 
}
/////////////////
//MAZE TRAVERSE//
/////////////////

//global
int startingFlag = 1, direction = 0;

//enumeration
enum Stat { OVER, NOT_OVER };

int mazeTraverse( int maze[ MAX ][ MAX ], int currentRow, int currentColumn, int size ){
   //sub-function
   int gameOver( const int currentRow, const int currentColumn, int size );
   int move( int maze[ MAX ][ MAX ], int *currentRow, int *currentColumn, int *currentDirection, int size );
   void printPosition( int maze[ MAX ][ MAX ], const int currentRow, const int currentColumn, int size );
   
   enum Stat State;
   
   //check if game is over
   State = gameOver( currentRow, currentColumn, size );

   if(State == OVER && startingFlag == 0){
      printPosition( maze, currentRow, currentColumn, size );
      return OVER; //return OVER indicating succesfully find the exit
      //algorithm for if this function can't find the exit is not available       
   }
   
   //indicate player is ready to move
   if(startingFlag == 1){
      //print initial maze
      printf("Player's ready\n**************\n");
      printPosition( maze, currentRow, currentColumn, size );
      system("pause");
      system("cls");
      //set first direction based on starting position
      if(currentRow == 0){
         direction = 1;              
      }else if(currentRow == 11){
         direction = 0;      
      }else if(currentColumn == 0){
         direction = 2;      
      }else if(currentColumn == 11){
         direction == 3;      
      }
      startingFlag = 0;             
   }  
   
   //seek for next move
   move( maze, ¤tRow, ¤tColumn, &direction, size );
   
   //system("pause");//activate this to see each move
   system("cls");
   
   mazeTraverse( maze, currentRow, currentColumn, size );
   
   return OVER;   
}

/*seek for next move*/
enum Direction { NORTH, SOUTH, EAST, WEST };
int move( int maze[ MAX ][ MAX ], int *currentRow, int *currentColumn, int *currentDirection, int size ){
   int posibble[ 4 ] = { 0 };// 1 -> North; 2 -> South; 3 -> East; 4 -> West;
   int counter = 0;
   
   enum Direction Seek; 
   
   Seek = *currentDirection;
   
   /*move the player respect to current direction*/
   
   //cover the current position
   maze[ *currentRow ][ *currentColumn ] = 0;
   
   //move the player respect to current direction
   if(Seek == NORTH){
      //print direction
      printf("direction = NORTH\n");
      //move north
      *currentRow -= 1;
   }else if(Seek == SOUTH){
      //print direction
      printf("direction = SOUTH\n");
      //move south
      *currentRow +=1;      
   }else if(Seek == EAST){
      //print direction
      printf("direction = EAST\n");
      //move east
      *currentColumn += 1;   
   }else if(Seek == WEST){
      //print direction
      printf("direction = WEST\n");
      //move west
      *currentColumn -= 1;
   }
   
   maze[ *currentRow ][ *currentColumn ] = 3;
   
   //print each move
   printPosition( maze, *currentRow, *currentColumn, size );// print maze with player current position
   
   /*analyse for next direction*/
   
   //seek posibble direction
   printf("Seek next direction...\n\n");
   if(maze[ *currentRow - 1 ][ *currentColumn ] == 0 && Seek != SOUTH){
      printf("NORTH is possible\n");
      posibble[ 0 ] = 1;
      counter++;
   }
   if(maze[ *currentRow + 1 ][ *currentColumn ] == 0 && Seek != NORTH){
      printf("SOUTH is possible\n"); 
      posibble[ 1 ] = 1;
      counter++; 
   } 
   if(maze[ *currentRow ][ *currentColumn + 1 ] == 0 && Seek != WEST && 
      maze[ *currentRow ][ *currentColumn + 1 ] != 4){
      printf("EAST is possible\n"); 
      posibble[ 2 ] = 1; 
      counter++; 
   } 
   if(maze[ *currentRow ][ *currentColumn - 1 ] == 0 && Seek != EAST){
      printf("WEST is possible\n");  
      posibble[ 3 ] = 1;
      counter++; 
   } 
   //if exit found
   if(maze[ *currentRow ][ *currentColumn + 1 ] == 4 && Seek != WEST){
      printf("Exit found\n"); 
      posibble[ 2 ] = 1; 
      counter++; 
   } 
   printf("\n");
   
   //follow right wall
   //Direction { NORTH, SOUTH, EAST, WEST };
   if(counter == 1){
      if(posibble[ 1 ] == 1){//south
         *currentDirection = 1;
      }else if(posibble[ 2 ] == 1){//east
         *currentDirection = 2;
      }else if(posibble[ 0 ] == 1){//north
         *currentDirection = 0;      
      }else if(posibble[ 3 ] == 1){//west
         *currentDirection = 3;
      }
   }else if(counter == 2){
      if(posibble[ 2 ] == 1 && posibble[ 3 ] == 1){// posibble: EAST, WEST
         if(Seek == SOUTH){
            *currentDirection = 3;
         }else if(Seek == NORTH){
            *currentDirection = 2;      
         }                
      }else if(posibble[ 0 ] == 1 && posibble[ 1 ] == 1){// posibble: NORTH,SOUTH
         if(Seek == EAST){
            *currentDirection = 1;        
         }else if(Seek == WEST){
            *currentDirection = 0;      
         }
      }else if(posibble[ 0 ] == 1 && posibble[ 3 ] == 1){// NORTHWEST
            *currentDirection = 0;        
      }else if(posibble[ 0 ] == 1 && posibble[ 2 ] == 1){// NORTHEAST
            *currentDirection = 2;        
      }else if(posibble[ 1 ] == 1 && posibble[ 2 ] == 1){// SOUTHEAST
            *currentDirection = 1;        
      }else if(posibble[ 1 ] == 1 && posibble[ 3 ] == 1){// SOUTHWEST
            *currentDirection = 3;        
      }
   }else if(counter == 3){
      if(Seek == NORTH){
         *currentDirection = 2;        
      }else if(Seek == SOUTH){
         *currentDirection = 3;      
      }else if(Seek == EAST){
         *currentDirection = 1;      
      }else if(Seek == WEST){
         *currentDirection = 0;      
      }
   }else if(counter == 0){
      //dead end
      if(Seek == NORTH){
         *currentDirection = 1;         
      }else if(Seek == SOUTH){
         *currentDirection = 0;      
      }else if(Seek == EAST){
         *currentDirection = 3;      
      }else if(Seek == WEST){
         *currentDirection = 2;      
      }
   }
   
}

/*check if game is over*/
int gameOver( const int currentRow, const int currentColumn, int size ){
   if(currentColumn == size * 2){
      return OVER;
   }else{
      return NOT_OVER;      
   }
   printf("position: (%d, %d)\n\n", currentRow, currentColumn);
}

/*print current position*/
 void printPosition( int maze[ MAX ][ MAX ], const int currentRow, const int currentColumn, int size ){
    int row, col;
   
   printf("\n");
   
   for(row = 0; row < size * 2 + 1; row++){
           
      if(maze[ row ][ 0 ] == START)
         printf(" START -> ");
      else
         printf("          ");
         
      for(col = 0; col < size * 2 + 1; col++){
         if(maze[ row ][ col ] == WALL)
            printf("#");
         else if(maze[ row ][ col ] == START)
            printf("X");
         else
            printf(" ");        
      } 
      
      if(maze[ row ][ size * 2 ] == END)
         printf(" <- END");
                
      printf("\n");
   }  
   printf("\n");  
 }

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