Bingo check

Problems/Bingo-Check/README.md

@@ -0,0 +1,43 @@
+# Bingo-Check
+
+Create a function that takes a 5x5 2D list and returns True if it has at least one Bingo, and False If it doesn't.
+
+## Infos which are maybe needed
+
+A board has a bingo, when a horizontal, vertical or diagonal 5 `x` line exists.
+
+## Documentation
+
+### Solution Idea
+
+The board is represented as a 2D array (an array containing other arrays).
+
+First, we check whether any inner array is completely filled with `"x"`.  
+If such an array exists, it means there is a horizontal line and we return `true`.
+
+If not, we check for vertical lines.  
+For each possible index (0 → 4), we check the same index in every inner array.  
+If all arrays contain `"x"` at that index, we have a vertical line and return `true`.
+
+Finally, we check the two diagonals:
+
+- positions `[i, i]`
+- positions `[i, 4 - i]`
+
+For each index `i`, we verify whether all elements on one of these diagonals are `"x"`.  
+If either diagonal contains only `"x"`, we return `true`.
+
+If none of these checks succeed, no winning line exists and the function returns `false`.
+
+---
+
+### [Implementation](./solver.ts)
+
+It`s really simple. There are just 3 different for-loops. I don't think there is a description necessary :)
+
+---
+
+### Information's
+
+This problem comes from the newsletter [Sloth Bytes](https://slothbytes.beehiiv.com).
+[Post](https://slothbytes.beehiiv.com/p/managing-data-is-complicated) from January 27, 2026.

Problems/Bingo-Check/bingo-check.test.ts

@@ -0,0 +1,79 @@
+import { describe, expect, it } from "vitest";
+import type { FixedArray } from "../../utilities/types/fixedArray";
+import bingoCheck from "./solver";
+
+type CardType = FixedArray<FixedArray<"x" | number, 5>, 5>;
+
+describe("Validates correctly if a Bingo-Card has a bingo on it or not", () => {
+	const firstCard: CardType = [
+		[45, "x", 31, 74, 87],
+		[64, "x", 47, 32, 90],
+		[37, "x", 68, 83, 54],
+		[67, "x", 98, 39, 44],
+		[21, "x", 24, 30, 52],
+	];
+
+	it("should return true for the horizontal bingo", () => {
+		expect(bingoCheck(firstCard)).toEqual(true);
+	});
+
+	const secondCard: CardType = [
+		["x", 43, 31, 74, 87],
+		[64, "x", 47, 32, 90],
+		[37, 65, "x", 83, 54],
+		[67, 98, 39, "x", 44],
+		[21, 59, 24, 30, "x"],
+	];
+
+	it("should return true for the diagonal bingo", () => {
+		expect(bingoCheck(secondCard)).toEqual(true);
+	});
+
+	const thirdCard: CardType = [
+		["x", "x", "x", "x", "x"],
+		[64, 12, 47, 32, 90],
+		[37, 16, 68, 83, 54],
+		[67, 19, 98, 39, 44],
+		[21, 75, 24, 30, 52],
+	];
+
+	it("should return true for the diagonal bingo", () => {
+		expect(bingoCheck(thirdCard)).toEqual(true);
+	});
+
+	const forthCard: CardType = [
+		[45, "x", 31, 74, 87],
+		[64, 78, 47, "x", 90],
+		[37, "x", 68, 83, 54],
+		[67, "x", 98, "x", 44],
+		[21, "x", 24, 30, 52],
+	];
+
+	it("should return false for no bingo", () => {
+		expect(bingoCheck(forthCard)).toEqual(false);
+	});
+
+	const fifthCard: CardType = [
+		[45, 43, 31, 74, 87],
+		["x", 29, 47, 32, 90],
+		[37, "x", 41, 83, 54],
+		[67, 98, "x", 58, 44],
+		[21, 59, 24, "x", 59],
+	];
+
+	it("should return false for a wrong vertical bingo", () => {
+		expect(bingoCheck(fifthCard)).toEqual(false);
+	});
+
+	const sixthCard: CardType = [
+		[21, 59, 24, 30, "x"],
+		[67, 98, 39, "x", 44],
+		[37, 65, "x", 83, 54],
+		[64, "x", 47, 32, 90],
+		["x", 43, 31, 74, 87],
+	];
+
+	it("should return true for the other diagonal bingo", () => {
+		expect(bingoCheck(sixthCard)).toEqual(true);
+	});
+});

Problems/Bingo-Check/solver.ts

@@ -0,0 +1,22 @@
+import type { FixedArray } from "../../utilities/types/fixedArray";
+
+export default function bingoCheck(card: FixedArray<FixedArray<"x" | number, 5>, 5>): boolean {
+	if (
+		card.reduce(
+			(preVal, row) => (preVal ? true : row.reduce((p, element) => (p ? element === "x" : false), true)),
+			false
+		)
+	)
+		return true;
+
+	let leftDiagonal = true;
+	let rightDiagonal = true;
+	for (let i = 0; i < card.length; i++) {
+		if (card.reduce((preVal, val) => (preVal ? val[i] === "x" : false), true)) return true;
+
+		if (!(leftDiagonal && card[i][i] === "x")) leftDiagonal = false;
+		if (!(rightDiagonal && card[i][4 - i] === "x")) rightDiagonal = false;
+	}
+
+	return rightDiagonal || leftDiagonal;
+}

README.md

@@ -8,9 +8,9 @@ This repository is about solving coding-problems. It contains famous (or not tha
 
 ## Problems
 
-Solved: **23 problems**
+Solved: **24 problems**
 
-🟢 Easy: 17  
+🟢 Easy: 18  
 🟠 Medium: 5  
 🔴 Hard: 1
 
@@ -39,6 +39,7 @@ Solved: **23 problems**
 | [One Two Skip a Few](./Problems/One-Two-Skip-A-Few/README.md)                           | 🟢 Easy    |
 | [Day number of year](./Problems/Day-Number-Of-Year/README.md)                           | 🟢 Easy    |
 | [Remove the last vowel](./Problems/Remove-The-Last-Vowel/README.md)                     | 🟢 Easy    |
+| [Bingo Check](./Problems/Bingo-Check/README.md)                                         | 🟢 Easy    |
 
 <!-- PROBLEMS_END -->
 

package.json

@@ -19,7 +19,8 @@
     "test:file": "vitest",
     "test:ci": "vitest --run --passWithNoTests --reporter=json > vitest-report.json",
     "build": "tsc",
-    "normalize": "biome check --write --unsafe",
+    "clear": "rm -rf ./build",
+    "normalize": "npm run clear && biome check --write --unsafe",
     "prepare": "husky install"
   },
   "dependencies": {

utilities/types/fixedArray.ts

@@ -0,0 +1,11 @@
+// Source - https://stackoverflow.com/a/60762482
+// Posted by Tomasz Gawel, modified by community. See post 'Timeline' for change history
+// Retrieved 2026-03-14, License - CC BY-SA 4.0
+
+type Grow<T, A extends Array<T>> = ((x: T, ...xs: A) => void) extends (...a: infer X) => void ? X : never;
+type GrowToSize<T, A extends Array<T>, N extends number> = {
+	0: A;
+	1: GrowToSize<T, Grow<T, A>, N>;
+}[A["length"] extends N ? 0 : 1];
+
+export type FixedArray<T, N extends number> = GrowToSize<T, [], N>;