Day 14 Mark

day 14/day_14_mark.js

+range = x => [...Array(x).keys()]
+
+robots = input.split("\n").map(line => line.match(/p=(-?\d+),(-?\d+) v=(-?\d+),(-?\d+)/).slice(1).map(Number))
+
+n = 103
+m = 101
+
+mod = (x,y) => ((x % y) + y) % y
+
+robotPosition = (robot, t) => [mod(robot[0] + t * robot[2], m), mod(robot[1] + t * robot[3], n)]
+
+positions = robots.map(robot => robotPosition(robot, 100))
+
+print = () => {
+	map = range(n).map(x => Array(m).fill(0))
+	positions.map(position => map[position[1]][position[0]]++)
+	console.log(map)
+	console.log(map.map(x => x.join('')).join('\n'))
+}
+
+inQuad1 = position => position[0] < (m-1)/2 && position[1] < (n-1)/2
+inQuad2 = position => position[0] > (m-1)/2 && position[1] < (n-1)/2
+inQuad3 = position => position[0] > (m-1)/2 && position[1] > (n-1)/2
+inQuad4 = position => position[0] < (m-1)/2 && position[1] > (n-1)/2
+
+output1 = [inQuad1,inQuad2,inQuad3,inQuad4].reduce((safetyFactor, inQuadX) => safetyFactor * positions.reduce((total, position) => total + inQuadX(position), 0), 1)
+
+////
+
+print = () => {
+	map = range(n).map(x => Array(m).fill(0))
+	positions.map(position => map[position[1]][position[0]]++)
+	console.log(map.map(x => x.map(y => y ? 'X' : ' ').join('')).join('\n'))
+}
+
+add = (x,y) => [x[0] + y[0], x[1] + y[1]]
+
+neighbourhood = x => [[-1,1],[1,1],[1,-1],[-1,-1]].map(y => add(x,y))
+
+isValid = x => (x[0] >= 0 && x[0] < m && x[1] >= 0 && x[1] < n)
+
+neighbour_score = (positions) => positions.reduce((total, position) => total + neighbourhood(position).filter(isValid).filter(x => map[position[1]][position[0]] > 0).length, 0)
+
+maxScore = 0
+maxScoreId = -1
+range(10000).map(i => {
+	positions = robots.map(robot => robotPosition(robot, i))
+	map = range(n).map(x => Array(m).fill(0))
+	positions.map(position => map[position[1]][position[0]]++)
+	score = neighbour_score(positions)
+	if(score > maxScore){
+		maxScoreId = i
+		maxScore = score
+		console.log(i, score)
+	}
+})
+
+output2 = maxScoreId