springer

gistfile1.js

function generateGrid() {
  console.time('generate grid');
  var grid = [];

  for(var i = 0; i < 10; i++) {
    grid[i] = [];
    for(var j = 0; j < 10; j++){
      grid[i][j] = {color: 'white'};
    }
  }
  console.timeEnd('generate grid');

  return grid;
}

var grid = generateGrid();

var moves = [
 {x: -2,  y: -1},
 {x: -1,  y: -2},
 {x: 1,   y: -2},
 {x: 2,   y: -1},
 {x: 2,   y: 1},
 {x: 1,   y: 2},
 {x: -1,  y: 2},
 {x: -2,  y: 1}
];

function possibleMoves(x, y) {
  console.time('possible moves');

  var possible = [];
  for(var i = 0; i < 8; i++) {
    var newX = x + moves[i].x;
    var newY = y + moves[i].y;
    if((newX >= 0 && newX < 10) 
      && (newY >= 0 && newY < 10)) {
      
      possible.push({x: newX, y: newY, num: newX*10 + newY});
    }
  }
  console.timeEnd('possible moves');

  return possible;
}

function possibleColorMoves(x, y, color) {
  console.time('possible color moves');
  var possible = [];
  for(var i = 0; i < 8; i++) {
    var newX = x + moves[i].x;
    var newY = y + moves[i].y;
    if((newX >= 0 && newX < 10) 
      && (newY >= 0 && newY < 10)
      && (grid[newX][newY].color === color)) {
      
      possible.push({x: newX, y: newY, num: newX*10 + newY});
    }
  }
  console.timeEnd('possible color moves');

  return possible;
}

function nextMove(x, y, color) {
  console.time('next move');

  var possible = possibleColorMoves(x, y, color);
  
  var next = {};

  if(possible.length > 0) {
    var lowest = {};
    var lowestNumber = 100;

    for(var i = 0; i < possible.length; i++) {    
      if(possible[i].num < lowestNumber) { 
        lowestNumber = possible[i].num;
        lowest = possible[i];
      }
    }
    lowest.color = grid[lowest.x][lowest.y].color;
    next = lowest;
  } else {
    var possibleTotal = possibleMoves(x, y);

    var highest = {};
    var highestNumber = 0;
    for(var i = 0; i < possibleTotal.length; i++) {    
      if(possibleTotal[i].num > highestNumber) {

        highestNumber = possibleTotal[i].num;
        highest = possibleTotal[i];
      }
    }
    highest.color = grid[highest.x][highest.y].color;

    next = highest;
  }
  console.timeEnd('next move');

  return next;
}

function flipColor(x, y) {
  grid[x][y].color = grid[x][y].color === 'white' ? 'black' : 'white';
}

function countBlacks() {
  var res = 0;
  for(var i = 0; i < 10; i++) {
    for(var j = 0; j < 10; j++) {
      if(grid[i][j].color === 'black') {
        res = res + 1;
      }
    }
  }

  return res;
}

function printGrid() {
  console.log('- - - - - - - - - - ')
  for(var i = 0; i < 10; i++) {
    var row = '';
    for(var j = 0; j < 10; j++) {
      if(grid[i][j].color === 'black') {
        row = row + 'x ';
      } else {
        row = row + 'o ';
      }
    }
    console.log(' ');
    console.log(row);
  }
}

function moveKnight(x, y, color, i) {
  // console.log('x: ' + x + ' - y: ' + y);
  // console.log('color: ' + color);
  // printGrid();

  if(i === 0) {
    console.log('number of blacks: ' + countBlacks())
    printGrid();
    return countBlacks();
  }

  var next = nextMove(x, y, color);
  flipColor(x, y);
  return moveKnight(next.x, next.y, next.color, i-1);
}