Year 2024, Day 9

clients/typescript/solutions/S2409.ts

@@ -0,0 +1,59 @@
+import ISolution from "./ISolution.ts";
+
+export default class S2409 implements ISolution {
+    firstPart(input: string): (number | string) | Promise<number | string> {
+        const numbers = input.split("").map(Number);
+        const map: (string | number)[] = [];
+        for (let i = 0; i < numbers.length / 2; i++) {
+            const size = numbers[ i * 2 ];
+            const space = numbers[ i * 2 + 1 ];
+            map.push(...Array.from({ length: size }).fill(i) as number[]);
+            map.push(...Array.from({ length: space }).fill(".") as string[]);
+        }
+        for (let i = map.length - 1; i > 0; i--) {
+            if (map[ i ] === ".") {
+                continue;
+            }
+            const lastIndex = map.indexOf(".");
+            if (lastIndex < i) {
+                map[ lastIndex ] = map[ i ];
+                map[ i ] = ".";
+            }
+        }
+        return map.reduce((acc: number, val, index) => {
+            if (val === ".") {
+                return acc;
+            }
+            return acc + (typeof val === 'number' ? val * index : 0);
+        }, 0);
+    }
+    secondPart(input: string): (number | string) | Promise<number | string> {
+        const numbers = input.split("").map(Number);
+        const map: (string | number)[] = [];
+        for (let i = 0; i < numbers.length / 2; i++) {
+            const size = numbers[ i * 2 ];
+            const space = numbers[ i * 2 + 1 ];
+            map.push(...Array.from({ length: size }).fill(i) as number[]);
+            map.push(...Array.from({ length: space }).fill(".") as string[]);
+        }
+        for (let i = map.length - 1; i > 0; i--) {
+            if (map[ i ] === ".") {
+                continue;
+            }
+            const length = map.filter(val => val === map[i]).length;
+            const first = map.indexOf(map[i]);
+            const lastIndex = map.map(x => x === "." ? x : "x").join("").indexOf(".".repeat(length));
+            if (lastIndex < i && lastIndex !== -1) {
+                map.splice(lastIndex, length, ...Array.from({ length }).fill(map[i]) as number[]);
+                map.splice(first, length, ...Array.from({ length }).fill(".") as string[]);
+            }
+        }
+        return map.reduce((acc: number, val, index) => {
+            if (val === ".") {
+                return acc;
+            }
+            return acc + (typeof val === 'number' ? val * index : 0);
+        }, 0);
+    }
+
+}