Knights tour iterative solution

knightsTour.cpp

#include <iostream>
#define B_SIZE 8

using std::cout;
using std::cin;
using std::endl;

bool checkBounds(int currentRow, int currentCol, int horiz, int vert);
int move(int currentRow, int currentCol, int * newCoordinates, int step);
void recordMove(int row, int col);
void undo(int currentRow, int currentCol, int step, int * newCoordinates);
void printBoard();
void printAccessibilityBoard();
void generateAccessibilityBoard();

int board[B_SIZE][B_SIZE] = {{0,0,0,0,0,0,0,0}};
int usedSquares[B_SIZE][B_SIZE] = {{0,0,0,0,0,0,0,0}};
//records how many moves are accessible from each position
int accessibilityBoard[B_SIZE][B_SIZE] = {{0,0,0,0,0,0,0,0}};
int moves[64] = {0};
//the step that was used last on a specific move
int stepOnMoveN[64] = {0};
int horizontal[8] = {2, 1, -1, -2, -2, -1, 1, 2};
int vertical[8] =   {-1, -2, -2, -1, 1, 2, 2, 1};

int main(){
  int status, currentRow = 3, currentCol = 3, step = 0;
  unsigned long moves = 0;
  int newCoordinates[2];
  //compiler will init the rest of the values to 0
  char i;
  //start at coord 0,0
  usedSquares[currentRow][currentCol] = 1;
  while(step < 63){
    printBoard();
    //cout << "\n";
    generateAccessibilityBoard();
    /*printAccessibilityBoard();
    cout << "Type 'n' for next move\n";
    cin >> i;    
    if (i == 'q') 
      return -1;
    */
    status = move(currentRow, currentCol, newCoordinates,step);

    if(status == -1){
      stepOnMoveN[step] = 0;
      undo(currentRow, currentCol, --step, newCoordinates);
      //increment to try next step
	stepOnMoveN[step]++;
     }
    else{
      step++;
    }
    currentRow = newCoordinates[0];
    currentCol = newCoordinates[1];
    moves++;
    cout << "\n Moves made so far: " << moves << "\n" << endl;
    //cout << step << "\n" << endl;
  }
  cout << "You win!\n";
  printBoard();
  return 0;
}

void generateAccessibilityBoard(){
  int count = 0;
  for(int i = 0; i < B_SIZE; i++){
    for(int j = 0; j < B_SIZE; j++){
      //for move in moves
      for(int k = 0; k < 8; k++){
	if(checkBounds(i, j, horizontal[k],vertical[k]) &&
	   usedSquares[i + vertical[k]][j + horizontal[k]] == 0)
	  {
	  count++;
	}
      }
      accessibilityBoard[i][j] = count;
      count = 0;
    }
  }
}
bool checkBounds(int currentRow, int currentCol, int horiz, int vert){
  if( (currentRow + vert < 0) || (currentRow + vert > 7) ||
      (currentCol + horiz < 0) || (currentCol + horiz > 7)
      ){
    return false;
  }
  return true;
}

int move(int currentRow, int currentCol, int * newCoordinates, int step){
  //if move is on board and the move hasn't been done, then try it.
  int min = -1, i, indexOfMin = 0;
  for(i = stepOnMoveN[step]; i < 8; i++){
    if (checkBounds(currentRow, currentCol, horizontal[i], vertical[i]) &&
	usedSquares[currentRow + vertical[i]][currentCol + horizontal[i]] == 0
	){
      if(min == -1){
	newCoordinates[0] = currentRow + vertical[i];
	newCoordinates[1] = currentCol + horizontal[i];
	min = accessibilityBoard[newCoordinates[0]][newCoordinates[1]];
	indexOfMin = i;
      }
      else if(accessibilityBoard[currentRow + vertical[i]][currentCol + horizontal[i]] < min){
	newCoordinates[0] = currentRow + vertical[i];
	newCoordinates[1] = currentCol + horizontal[i];
	min = accessibilityBoard[newCoordinates[0]][newCoordinates[1]];
	indexOfMin = i;
      }
    }
  }
  //no possible moves
  if(min == -1){
    return -1;
  }
  else{
      usedSquares[newCoordinates[0]][newCoordinates[1]] = 1;
      stepOnMoveN[step] = indexOfMin;
      //cout << "step on move " << step << " :" << stepOnMoveN[step] << "\n" << endl;
      cout << "Moved to: " << newCoordinates[0] << ", " << newCoordinates[1] << endl;
  }
  return 0;

}
/* undo last move */
//go back to move at step -1 and decrement step
void undo(int currentRow, int currentCol, int step, int * newCoordinates){
  usedSquares[currentRow][currentCol] = 0;
  newCoordinates[0] = currentRow + (-1 * vertical[stepOnMoveN[step]]);
  newCoordinates[1] = currentCol + (-1 * horizontal[stepOnMoveN[step]]);
  cout << "UNDO! Moved back to: " << newCoordinates[0] << ", " << newCoordinates[1] << "\nFrom: " << currentRow << ", " << currentCol << "\n" << endl;
}

void printBoard(){
  for(int i=0; i< B_SIZE; i++){
    for(int j = 0; j < B_SIZE; j++){
      if(usedSquares[i][j] == 1)
	cout << 1;
      else cout << 0;
      cout << " ";
    }
    cout << endl;
  }
}

void printAccessibilityBoard(){
  for(int i=0; i< B_SIZE; i++){
    for(int j = 0; j < B_SIZE; j++){
      cout << accessibilityBoard[i][j];
      cout << " ";
    }
    cout << endl;
  }
}