Karat Puzzle

rectangle-puzzle.js

/*var _ = require('underscore')

function sayHello() {
  console.log('Hello, World');
}

_.times(5, sayHello);
*/
var image = [
  [1, 1, 1, 1, 1, 1, 1],
  [1, 1, 1, 1, 1, 1, 1],
  [1, 1, 1, 0, 0, 0, 1],
  [1, 1, 1, 0, 0, 0, 1],
  [1, 1, 1, 1, 1, 1, 1]
];

var image = [
  [1, 1, 1, 1, 1, 1, 1],
  [1, 1, 1, 1, 1, 1, 1],
  [1, 1, 1, 0, 0, 0, 1],
  [1, 0, 1, 0, 0, 0, 1],
  [1, 0, 1, 1, 1, 1, 1],
  [1, 0, 1, 0, 0, 1, 1],
  [1, 1, 1, 0, 0, 1, 1],
  [1, 1, 1, 1, 1, 1, 1],
];

function findAPixel(image) {
  var height = image.length;
  var width = image[0].length;
  var x,y;
  
  // naive solution first, search whole image
  for (y=0; y<height; y+=1) {
    for (x=0; x<width; x+=1) {
      if (image[y][x] === 0) {
        return { x: x, y: y};
      }
    }
  }
}

function solveTheSize(image, coords) {
  // will have x,y, width, height
  var height = image.length;
  var width = image[0].length;  
  var rect = { x: coords.x, y: coords.y };
  
  // find the upper-left corner first
  var upperX, upperY;
  for (upperX = rect.x; upperX > 0; upperX -= 1) {
    if (image[rect.y][upperX] === 1) {
      rect.x = upperX + 1;
      break;
    }
  }
  
  for (upperY = rect.y; upperY > 0; upperY -= 1) {
    if (image[upperY][rect.x] === 1) {
      rect.y = upperY + 1;
      break;
    }
  }
  
  // find the width and height of the rectangle
  var lowerX, lowerY;
  for (lowerX = rect.x; lowerX < width; lowerX += 1) {
    if (image[rect.y][lowerX] === 1) {
      rect.width = lowerX - rect.x;
      break;
    }
  }
  
  for (lowerY = rect.y; lowerY < height; lowerY += 1) {
    if (image[lowerY][rect.x] === 1) {
      rect.height = lowerY - rect.y;
      break;
    }
  }
  
  return rect;
  
}

var aPixel = findAPixel(image);
var dimensions = solveTheSize(image, aPixel);
console.log(aPixel);
console.log(dimensions);


/* 
Your previous Markdown content is preserved below:


var image = [
  [-1, 1, 1, 1, 1, 1, 1],
  [1, -1, 1, 1, 1, 1, 1],
  [1, 1, -1, 0, 0, 0, 1],
  [1, 1, 1, -0, 0, -0, 1],
  [1, 1, 1, 1, 1, 1, -1]
];

var answer = {
  top: [2,3], // y coord, x coord
  width: 3,
  height: 2
}

image[0][0]

image[1][0] // down
image[0][1] // right


 */