Day 3

03/part1.js

@@ -0,0 +1,52 @@
+const fs = require('fs')
+const readline = require('readline');
+
+const readInterface = readline.createInterface({
+    input: fs.createReadStream('input'),
+    console: false
+});
+
+
+// array of arrays of bool. Coordinates are [y][x]. True = tree.
+let map = [];
+
+readInterface.on('line', function(line) {
+  let row = [];
+  
+  line.split('').forEach(function(char) {
+    if (char == '.') {
+      row.push(false);
+    } else if (char == '#') {
+      row.push(true);
+    }; // ignore any other character
+  });
+  
+  console.log(line);
+  console.log(row);
+
+  map.push(row);
+});
+
+readInterface.on('close', function(line) {
+  let treesHit = 0;
+  let x = 0;
+  let y = 0;
+
+  while (y + 1 < map.length) {
+    x += 3;
+    y += 1;
+
+    if (x + 1 > map[y].length) {
+      x -= map[y].length;
+    }
+
+    if (map[y][x]) {
+      treesHit++;
+    }
+
+    console.log(x, y, map[y][x]);
+  }
+
+  console.log(treesHit);
+});
+