day 2

.vscode/launch.json

@@ -0,0 +1,24 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "request": "launch",
+            "name": "Launch Program",
+            "type": "node",
+            "program": "${workspaceFolder}/main.ts",
+            "cwd": "${workspaceFolder}",
+            "env": {},
+            "runtimeExecutable": "/Users/okaup/.deno/bin/deno",
+            "runtimeArgs": [
+                "run",
+                "--unstable",
+                "--inspect-wait",
+                "--allow-all"
+            ],
+            "attachSimplePort": 9229
+        }
+    ]
+}

2/exampleInput.txt

@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9

2/task.ts

@@ -0,0 +1,87 @@
+import { readLines } from "../utils.ts";
+
+export async function solveTask2part1() {
+    const lines = await readLines('./2/input.txt');
+
+    let safeReports = 0;
+    for (const line of lines) {
+        const numbers = line
+            .split(' ')
+            .map( n => parseInt(n.trim()) );
+        
+        const checkNumbers = (numbers:number[]) => {
+            let order:string|undefined = undefined;
+            for (let i = 1; i < numbers.length; i++) {
+                const prevN = numbers[i-1];
+                const n = numbers[i];
+                const diff = n - prevN;
+                if (!order) {
+                    order = diff < 0 ? 'desc' : 'asc';
+                } else {
+                    if (order === 'asc' && diff < 0) return false;
+                    if (order === 'desc' && diff > 0) return false;
+                }
+                const diffAbs = Math.abs(diff);
+                if (diffAbs < 1) return false;
+                if (diffAbs > 3) return false;
+            }
+            return true;
+        }
+        const result = checkNumbers(numbers);
+        if (result) safeReports++;
+
+    }
+
+    console.log('safeReports', safeReports)
+}
+
+
+export async function solveTask2part2() {
+    // const lines = await readLines('./2/exampleInput.txt');
+    const lines = await readLines('./2/input.txt');
+
+    let safeReports = 0;
+    for (const line of lines) {
+        const numbers = line
+            .split(' ')
+            .map( n => parseInt(n.trim()) );
+        
+        let badLevelRemoved = false;
+        const checkNumbers = (numbers:number[]):boolean => {
+            const handleBadLevel = ():boolean => {
+                if (badLevelRemoved) return false;
+                badLevelRemoved = true;
+                const possibilities = new Array(numbers.length).fill(undefined)
+                    .map( () => structuredClone(numbers) );
+                possibilities.forEach( (n, i) => n.splice(i, 1) );
+                
+                const anyLvlRmvdWorks = possibilities
+                    .map( n => checkNumbers(n) )
+                    .some( check => check )
+
+                return anyLvlRmvdWorks;
+            }
+            let order:string|undefined = undefined;
+            for (let i = 1; i < numbers.length; i++) {
+                const prevN = numbers[i-1];
+                const n = numbers[i];
+                const diff = n - prevN;
+                if (!order) {
+                    order = diff < 0 ? 'desc' : 'asc';
+                } else {
+                    if (order === 'asc' && diff < 0) return handleBadLevel();
+                    if (order === 'desc' && diff > 0) return handleBadLevel();
+                }
+                const diffAbs = Math.abs(diff);
+                if (diffAbs < 1) return handleBadLevel();
+                if (diffAbs > 3) return handleBadLevel();
+            }
+            return true;
+        }
+        const result = checkNumbers(numbers);
+        if (result) safeReports++;
+
+    }
+
+    console.log('safeReports', safeReports)
+}

main.ts

@@ -1,4 +1,8 @@
 import { solveTask1part1, solveTask1part2 } from "./1/task.ts";
+import { solveTask2part1, solveTask2part2 } from "./2/task.ts";
 
-await solveTask1part1();
-await solveTask1part2();
+// await solveTask1part1();
+// await solveTask1part2();
+
+await solveTask2part1();
+await solveTask2part2();

utils.ts

@@ -0,0 +1,11 @@
+export async function readLines(path: string) {
+    const decoder = new TextDecoder("utf-8");
+    const inputData = await Deno.readFile(path);
+    const input = decoder.decode(inputData);
+    
+    // console.log(input.substring(0,50) + '...');
+    const lines = input.split('\n')
+        .filter( l => l.trim() !== '');
+
+    return lines
+}