04_2

day04/index.js

@@ -0,0 +1,44 @@
+import { readFileSync } from "fs";
+
+const input = readFileSync("pairs.txt", "utf-8");
+const assignments = [];
+
+let pairs, countPairs = 0, countOverlap = 0;
+
+input.split('\n').forEach(pair => {
+    for(let i = 0; i < 2; i++) {
+        assignments[i] = [];
+        for(let j = 0; j < 99; j++) {
+            assignments[i][j] = ".";
+        }
+    }
+
+    pairs = pair.split(',');
+
+    const betweenOne = pairs[0].split('-').map(x => parseInt(x));
+    const betweenTwo = pairs[1].split('-').map(x => parseInt(x));
+
+    for(let i = betweenOne[0]; i <= betweenOne[1]; i++) {
+        assignments[0][i - 1] = i;
+    }
+
+    for(let i = betweenTwo[0]; i <= betweenTwo[1]; i++) {
+        assignments[1][i - 1] = i;
+    }
+
+    let isOneInside = true, isTwoInside = true, foundOverlap = false;
+
+    for(let i = 0; i < 99; i++) {
+        if(assignments[0][i] !== "." && assignments[0][i] !== assignments[1][i]) isOneInside = false;
+        if(assignments[1][i] !== "." && assignments[0][i] !== assignments[1][i]) isTwoInside = false;
+        if(assignments[0][i] !== "." && assignments[0][i] === assignments[1][i] && !foundOverlap) {
+            foundOverlap = true;
+            countOverlap++;
+        }
+    }
+
+    if(isOneInside || isTwoInside) countPairs++;
+});
+
+console.log(countPairs)
+console.log(countOverlap)