9

src/2022/day9/index.ts

@@ -0,0 +1,47 @@
+import path from 'path';
+import { readFile, sum } from "../../utils";
+
+let input = readFile(path.resolve(__dirname, 'input.txt'));
+
+let grid: any[] = [];
+
+let right = 0;
+let up = 0;
+
+let THistory: {x:number, y:number}[] = [];
+
+let pos = {
+   
+    H: { x: 0, y: 0 },
+    T: { x: 0, y: 0 }
+}
+
+input.split("\n").forEach(element => {
+    const [dir, num] = element.split(" ");
+
+    for (let n = 0; n < num; n++) {
+        const prevH = {x: pos.H.x, y: pos.H.y}
+        switch (dir) {
+            case "U":
+                pos.H = { x: pos.H.x, y: pos.H.y + 1 };
+                break;
+            case "D": 
+                pos.H = { x: pos.H.x, y: pos.H.y - 1 };
+                break;
+            case "L":
+                pos.H = { x: pos.H.x - 1, y: pos.H.y };
+                break;
+            case "R":
+                pos.H = { x: pos.H.x + 1, y: pos.H.y };
+                break;
+        }
+
+        const distX = Math.abs(pos.H.x - pos.T.x);
+        const distY = Math.abs(pos.H.y - pos.T.y);
+        if(distX > 1 || distY > 1) pos.T = {x: prevH.x, y: prevH.y};
+
+        THistory.push(pos.T);
+    }
+}); 
+
+console.log("Part 1:", new Set(THistory.map(pos => pos.x + "-" + pos.y)).size);