A Pen By
Johan Karlsson

` ````
<h1>Advent of Code 18 Part 2</h1>
```

` ````
var size = 6;
var on = "#";
var off = ".";
// Game of Life, sort of...
function animateOneStep(lights) {
var newLights = deepClone(lights);
var currentRow;
for(var y = 0; y < lights.length; y++) {
currentRow = lights[y];
for(var x = 0; x < currentRow.length; x++) {
var nrOfNeighboursOn = calcNrOfNeighborsOn(lights, x, y);
var currentIsOn = isOn(lights, x, y);
if(currentIsOn && (nrOfNeighboursOn === 2 || nrOfNeighboursOn === 3)) {
setLight(newLights, x, y, on);
} else if (!currentIsOn && nrOfNeighboursOn === 3) {
setLight(newLights, x, y, on);
} else {
setLight(newLights, x, y, off);
}
}
}
return newLights;
}
function animate(lights, iterations) {
for(var i = 0; i < iterations; i++) {
lights = animateOneStep(lights);
}
return countLightsOn(lights);
}
function calcNrOfNeighborsOn(lights, x, y) {
return isOn(lights, x-1, y-1) +
isOn(lights, x , y-1) +
isOn(lights, x+1, y-1) +
isOn(lights, x-1, y ) +
isOn(lights, x+1, y ) +
isOn(lights, x-1, y+1) +
isOn(lights, x , y+1) +
isOn(lights, x+1, y+1);
}
function isOn(lights, x, y) {
if(x < 0 || y < 0 || x > size-1 || y > size-1) {
return 0;
} else {
var light = lights[y][x];
return light === on ? 1 : 0;
}
}
function deepClone(arr) {
var len = arr.length;
var newArr = new Array(len);
for (var i = 0; i < len; i++) {
if (Array.isArray(arr[i])) {
newArr[i] = deepClone(arr[i]);
}
else {
newArr[i] = arr[i];
}
}
return newArr;
}
function countLightsOn(lights) {
return lights
.map((row) => row.split("#").length-1)
.reduce((prev, current) => prev + current);
}
String.prototype.replaceAt = function(index, character) {
return this.substr(0, index) + character + this.substr(index + character.length);
}
function isCornerLight(x, y) {
if((x === 0 && y === 0) ||
(x === 0 && y === size-1) ||
(x === size-1 && y === 0) ||
(x === size-1 && y === size-1)) {
return true;
}
return false;
}
function setLight(lights, x, y, onOrOff) {
// The corner lights are always on
if(!isCornerLight(x, y)) {
lights[y] = lights[y].replaceAt(x, onOrOff);
}
}
describe("Calculate neighbors", function() {
var lights;
beforeEach(function() {
size = 6;
lights = [
".#.#.#",
"...##.",
"#....#",
"..#...",
"#.#..#",
"####.."
];
});
it("should return 2 (at a corner)", function() {
var result = calcNrOfNeighborsOn(lights, 0, 5);
expect(result).toBe(2);
});
it("shoult return 2 (at an edge)", function() {
var result = calcNrOfNeighborsOn(lights, 1, 1);
expect(result).toBe(2);
});
it("should return 4", function() {
var result = calcNrOfNeighborsOn(lights, 4, 1);
expect(result).toBe(4);
});
});
describe("Count lights on", function() {
var lights = [
".#.#.#",
"...##.",
"#....#",
"..#...",
"#.#..#",
"####.."
];
size = 6;
it("shoult return 15", function() {
var result = countLightsOn(lights);
expect(result).toBe(15);
});
});
describe("replaceAt", function() {
it("shoult replace i -> o", function() {
var result = "Hi".replaceAt(1, "o");
expect(result).toBe("Ho");
});
});
describe("Animate", function() {
var lights;
beforeEach(function() {
size = 6;
lights = [
"##.#.#",
"...##.",
"#....#",
"..#...",
"#.#..#",
"####.#"
];
});
it("shoult return 18", function() {
var result = animate(lights, 1);
expect(result).toBe(18);
});
it("shoult return 18 (again)", function() {
var result = animate(lights, 2);
expect(result).toBe(18);
});
it("shoult return 4", function() {
var result = animate(lights, 4);
expect(result).toBe(14);
});
});
// The data for the real Advent of code puzzle
var lights10000 = [
"#...##......#......##.##..#...##......##.#.#.###.#.#..#..#......####..#......###.#.#....#..##..###.#",
"####..#.#...#....#.#####.##.##.#..#.......#....#.##...###.###..#.#.#........#..#.#.##...##..#.####.#",
"...#..##...#.#.###.#.###..#.##.####.###...#...........#.###..##.#.##.#.###...#.#..###....#.###.#..#.",
".#...##...####.#..#.....#..#...#.#.##...#...##..#.#.###....#..###.....##..#.###..###.....##..###...#",
"..##.#####....##..#.#..##.##..######...#..###.######.....#..##...#.#..##..##..#..#..#..##.#.#.#.#...",
".###.###.###...##...##..###..##.###.#.....##..##.#.#########...##..##.#..##.#..##..####..#.#.#.#####",
"#.#####..###.###.##.##.#...#.#.#.#..#.###...#..##.###.#...####.#..#.#.....###..#..####..#.#.#...##..",
"....#...##.....#....####.##.#.###..#.#.##..#.#...##.###.###..#.##..#.#.##..##..#.##.###..#.#.###.###",
"##.##...#.##...#.#..#.#..#...###...###.#..#..#.#####..###.#......#.....###.#####.#.#..#.#.#.##..#.#.",
"#.#..#.....#.....##.#..##...###..##...##...###.#.###.#..#.#.###...##..##..#.###...#.#######.#...#.#.",
"#.#.....####.#..#.##...#.##....#####.###.#.....#####....###..#........##..####...#...#.###....#..###",
"##.#.##..#.#.##.#.....##.#.....###.####.#..######.....####.#.#..##.#.##...#..#.#.....#.####.#.......",
"#..#..#.#..#.######.##..##.####.....##.#.##.#.######..#.#....#.#...#.#..#..#.#.###.#..#.#.#..#...###",
"####..####.#.#.###.....#.#.#.##..#.##.##.##.#..##..##.#.##.....#.#..#.####.....###.#..#.####.#.#..##",
"###.##..##.#.##..#..##...#.#####.##.#....##.####.#.##....#..###.#.#.##...#.....#.#.#.#.#..##.#.#..#.",
"......#..####...##.##...#.##.##...##..#..##.###..#...#..##...#.#....###.####...#.##.###.#.##.####.##",
"..#...#####.#.#..#.##....#..#...#..####.....###...##.###....#..#.###...#........#.#.##..#..#.#.....#",
"#######.#.#.###.###..######.##..#####.##.###.###....####.#..##.##...###.#..############.#.##....##.#",
"#.#...##.###.#.###..#.#.#.#.#.#..##..####.#..##.....#.##..#.##...##.#..##..#.#.#....##....##.#..#.#.",
"..#.#.####.....###..#######.#.#.#.#...##.#####.....##...##...##.###..######.###..#...####.#..###.###",
".#.##....#.#.##..##.#.##.##..######...#.....#..#.#.#.#.....#.#..##.#.#.......#######....#.......#...",
"..###.##.##..##....#.###...#.....##..##......###...##..###.##...##.###.#.#.#.###.###.#.#...###..#...",
".##.#.#...#...##.#.#...#..#..#.#...##.#.##...##..#....#.#..##.#..#.#..#.#.....#..#.#...#######.#.##.",
"...####....#.###.#..###..##...##..#.#.#.###...#..##.##.##..##.#...#..#.##.....#.#........#..#.#.####",
".....##..###...#....#.#.#.#...###.###...#.#...#.#.####....#..####...###..#..######..##.##..###.#####",
"#####.##..#....###.###....##.....#.#..#....#.#####.##.#.####.#.##...#..###...###..##...#.###.#####..",
"###.##..........########.######....####.###.#..##...#.##.####.#.....##..#####..###...#####.....#.#.#",
"##..#####.##.#.#####.#.##.##..#.##....########.#####.#...#.###.##...#.###.#.#..#....##.#..#...#.#.#.",
".##.#....#..#...#..#####..#..##.#......#..#....########...#..#...#.....####.#...##...#.###.#.#..##.#",
".##.##.#.##.#.##...#.#.#..##.##.###.#..##..#...###.##.###.#####.#.###..#..###.#...#.###.#...#..#.#.#",
".#..#..#.#..#..###..#....###.####.##.#.###.#.##.###.#.##.###.###...###...###.#...####...#.##.##.#.#.",
"###..##...###...#..##.#..#.#...##....###.##.##..#####....###..#..#....#..###.###.#...#.##...#.#.#..#",
"#....#.......##.....#.##...#..#.###.#.##..##..#.##..#.###..##.##...#####.#..#####..#####..#####....#",
".####.####....###..###.#.##.####.##.#...####.#.###.#.....#...####..#####.###..#.#.###.##.##...##..#.",
"####..##...##.########...##..###..#..###.##.#.#.#........#.#####.#...#.###.####.#..####..#.#.#....##",
"###.#..#...###.#..#..#.###...##..###.##.#.#...#..#...####..##....#.#..#..##.#.#...#####.###.#..#.#.#",
"...##....#.###.#.#..##...##.###.#..#..#......#...#.#..####.#.##..######.####.#...#..#..#..##.#.#.##.",
"##.####.#...#..#.#.##..##.#.#.###..##...####......#..######.#......#.##.#....##...###.#.#..#......##",
"#.....#...#######.##.#..#.#...###.#..#.####....#.#.##.#.##...###..#...#.###.##..#.###..#.##...#####.",
"#####.##...#..#.#.#.......#.##..#####..#####...###..##.#.#..###.#.#####.####..#.#..##...#.##...#.###",
".##.#..#######.###.#.####.....##...#.##.#.#..#...##....####......######.#..######.....##########.##.",
"##...#.#..#.##.###.#.#.#.##.###.##..##.##.##...#.#..###.#######..#.....#####..#....######.#..##..###",
".#.#.###.....#..##..#.#..##..#.###...###.#..##...#...#.#####.#.#####..###.#..#...##..#.#..#..####...",
".#......##..#.....####.###....##.###.....###.##........#.###.##..#..#.#######.#.######..##..###.....",
"..##.#.#..#.##...#.###.###...######..#..#.#..#....###.#.#....#..........#...##.##.##.#..##..#.#####.",
"###.###.#..#.##..##.#..#..##.....##.....#..#######.#..#.#.#.####.###..###.#.#..#.##.##.####.###.####",
"#.#.#..#....########.#..#..#...##..#.##..#.#..##..####...##.....#.##.#.#...########..#.###.#..#.#.##",
".##.....#...#.#...##.##....###...##..#.####...#..#.#..#..#.##..#.###.##.####.##..####.....##.#.....#",
"....####.#.##.#.##.#..##.#.######.##.####..#...####.#..###.#.#..#..##.#.#.....##.#####.#.####...#.#.",
"#..#####.#####.....##....######..##....#..#.#.###.#####.....##.##.####.#...##...#.##.#.#####.##.#...",
"##.####..###.#....#...#.#.#.#.###.#####.#.####..####...####......##..#..#..#.#.##...########....#...",
".###.#.#.#.#..####.##.#..######..#.#.###.....#.#......#.#.#.#..####.##...##.#####.#.##..##..#..#.#..",
".....###...#...#.####.###.#.#.#.#.....#....#.####.###.##.##.##.#######......#.####......#....##.....",
"##..#..#.#.##..#...#..##.##.##..###.#....##.##....####.#.##.###....#.##.#.#.##...##.###...#..#..####",
"...#.#..##..##.#...##.##...#.#......#.#.##..###....####.##...#.#.###.#..#..#.####..##..##..#####.###",
".##.##..##########.##...#.##.####.#.#######.##.#.##.##..#...##....########.###..##.##.##.#..##.#.#.#",
"#####.#....#.##..#.....#......##.##..#.##.###..##.......###..##.#.###.##.###....####.#..#.###..#.#.#",
".#...#..#.##....##....#...####....#...#..#...####...########.###.#..##.#.#.##..###..#.#.###.....##.#",
"##..##.....###......#..###.##.####.##.####.#.#....#..#...#..#.#..#.###.#...#...#..##.##...#..#######",
".....##..###..##...#####.#.#.....###.#.#..####...#.#.#..#..####..##.#..###.####.#....##..###....#..#",
"#.#.##.#....#.#####.#....##...#...##...##....#.#.......#....#..#...###.###.#.####..####....#.##.#.#.",
"..##...##..###.#.#.##.#..#....#.#.....##.###.#.###.###.....#...#.#..#######.#####..#.###...##......#",
"#......###..#....#.#..#.###.##.#...##..###.####.#.#....#.##..#.###..##.#..#####..##.###.....#..###..",
"##.#.##..##.###.#..##.....#.##.....###....##.####.######.#...#..###....#.#...#.##.....###....#..#.#.",
".##.#.#.#.##..#.#.#..##..#.###.####....#..###.######..####.#.....###.##..#...###.#..######.##.#.##..",
"...##.####.#..##.#####.##.#...##..#..#...#.#.#.#####...#....#..###...#..#....#.#.##.#.######.#..####",
"..#.#.#.#...#.######.#.....#..#.#..###....#.#.########...#....#.#.##..#...##...#.#..#.#.###....##...",
"#####..#..##..#..##..#..#.#.##.#....#####.####.##.#.###..##..##....#.....#.#####.#...#.#####.##.#.#.",
"#.#..#####...####.###.###.....####.###.....##...##...#..#..#######.#.##....##..####.....##...#..#..#",
"#.#.###.#.#..##..#....#.#...#.#.##.##..#.##.....##...#.#..##.......##.#.###..#####.#.##....#.##.....",
"...#.......#....#.#.####.#.###.###..#....#..##.#..####........#.##..#...#.#...###.#..#.#.#...#...#..",
"...##.#####.##.#.###.##.##.#.##..##.#.#.#.#.#.##.#..##...##.#.#..#..##.##.#####.#.###...#####..#..#.",
"#######.#..#..#....##.#.#..####.#..#..###...#..#.......###.#.#.####....#.###...#.#.###.#.#.#.#..###.",
"..##.##.#.##.###....###.##.#.###.#...#....#.####..###..###.#.#..#...##.#.#.#..##.###..###.#.##...###",
"######..######..##..##.#.#.##.##.#..##..#.#.#.##..#.#...#...#.#.#..######.#..#.#.######..#......##.#",
"#.#####.....#.......#########..###.##...#...##.#.#..#...#####...#...#..#.###.#..#.#...###.#.#.#...#.",
"#....##....###...##.##.#...##.........##.#.#..#.#.##.#.######.#####..#..###.###.#...#.#.##.######...",
"#.#...###.#.###.##.#.######.#######.###.##..#.#.#...######.##.####.##..#.#.#.#......##..##.........#",
"..###..##....#.....##...#.#.###.#.#.....##.#...###.####.#...#...##..##.#.#.####..###...######....#.#",
"..###.#.##.####.#..#.##....##..#####....#..##.##.#..#######...#.####...##.#.#.##.........#....#....#",
".##.#...#.####..#.#...#.##..######.##..##.#.###.##..###.###....##..#.##.##..##.#...###.##.##.###....",
"#...###.###.#..#....#.......#..#.....###..#.###.##.##....#.####.#.####.##..##..#..#.....#....##.#.#.",
".##.#..#..#.##.......#.####.#######.....#.##.##.#.....#.#..#....######.#..###.##.##.....#.####..##.#",
"###..#.###.#..####.....##....#..####....#.##.##..#...######.#########...#.#....##...###.#..#.##...#.",
"#..###..##..#.#.##.###.#.#.##...###.#...##.##..#.###....###..#.#...#.###..######.#..#.###..#..#..#.#",
".#........##.#.###..###.#.#.##.....##.##.#.#...##..#.##....###..#.#.#.#.##....#.##..#.#...###...#...",
"####.####..#....#.#.#..#..##.......##.####...###.##..#.#.##.#..##..######.......##.#.##..#...#.....#",
"..#..#..###..##.##..######.#..###..###.#.##..##.#..#####.#.#.#.##..#.##..##.##......####.#..........",
"...##.##..###.#...###....#.#.#.#.....#.##.....##...#...#......####...##.##....##.#..#.####.#..###.#.",
"..#.....####.#.###.#####..#..###..#..#.#...#####...###.###....#.###..#...#..#..#.#..#.##..##.#.#....",
"..##.#####...###.###.........#....##.####.##..#.#..#.#...#...##.##.##..#.#.##.########......#####...",
"...###.#.#..#...#.###.###.......##.###.#..#.##########...#..#.#.#.##.#.###...######..#.#...###.##...",
".#.#.#######.#..##.##..##...#...####...#..#####.#..##...###.#.#...#.##...#......#..##.####..#.....##",
".##.##.#.#......#######..###.....##.#.##..###......#....####...#.###.#.##.#........#..#....##.....##",
"#...#.###.#.##...##.####....#...#.###..#.#.....#.#....#.#.#.##...#.#..#####.#.#..#..#..#....#...####",
".....##...###......#####..##.##.##...##.#.#####..##...#.#.#.#.###...###.##.####..#.#..#.#..#.####.##",
"#..#..##.#.##.#.##.#.#.#..###....###.##.#.##.#...#.#..#...#....###.#..#.#.######.#...####..#..##.#.#",
"#..#.#..#...###.#..##.#...#...##.#......#...#..#..####..##.....#.###...#.#..#.#....#.#####.##.###...",
"###....#.#..#.#..###..#.##......#...#..#..##.#..###..##..#..#.####..#...########..##.#.##.#.#.#...#.",
"##.#.##.##.###..#...#.#....#..#.##..#.#.#.#.##.##.#####...#........####..###..####.#####..#.##.#.###"];
size = 100;
console.log("Lights on: " + animate(lights10000, 100));
```

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