Seven boom

Problems/Seven-Boom/README.md

@@ -0,0 +1,50 @@
+# Seven-Boom
+
+Create a function that takes an array of numbers and for every 7 found, add one "Boom!" to your result. If no 7 is found anywhere, return "there is no 7 in the array".
+
+## Infos which are maybe needed
+
+If e.g there is a `77` in the array, the count of 7's needs to increase by two.
+
+## Documentation
+
+### Solution Idea
+
+First, combine all numbers into a single string.  
+Then count how many times the digit `"7"` appears in that string.
+
+- If the count is `0`, return that there is no `"7"`.
+- If the count is greater than `0`, return `"Boom!"` repeated as many times as the digit `"7"` appears.
+
+---
+
+### [Implementation](./solver.ts)
+
+First, the array is joined into a single string using `array.join("")`.  
+Then we split the string again with `split("")`, which results in an array containing every single digit.
+
+Next, we use `reduce` to count how many times the digit `"7"` appears.  
+The reducer keeps track of the current count of sevens.
+
+If the current value is `"7"`, we increase the counter by 1.  
+Otherwise, we return the counter unchanged.
+
+Example reducer:
+
+.reduce((count, current) => (current === "7" ? count + 1 : count), 0)
+
+After this step, we have the total number of `"7"` digits stored in `sevenCount`.
+
+Finally, we check the value of this counter:
+
+- If it is `0`, we return the message that there is no `"7"`.
+- If it is greater than `0`, we return `"Boom!"` repeated `sevenCount` times using:
+
+`"Boom! ".repeat(sevenCount).trim();`
+
+---
+
+### Information's
+
+This problem comes from the newsletter [Sloth Bytes](https://slothbytes.beehiiv.com).
+[Post](https://slothbytes.beehiiv.com/p/how-does-google-maps-find-the-fastest-route) from February 25, 2026.

Problems/Seven-Boom/seven-boom.test.ts

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+import { describe, expect, it } from "vitest";
+import sevenBoom from "./solver";
+
+describe("Determines the correct count of sevens in the array", () => {
+	it("should return one 'Boom!' for the first array", () => {
+		expect(sevenBoom([1, 2, 3, 4, 5, 6, 7])).toEqual("Boom!");
+	});
+
+	it("should return 'there is no 7 in the array' for the second array", () => {
+		expect(sevenBoom([8, 6, 33, 100])).toEqual("there is no 7 in the array");
+	});
+
+	it("should return one 'Boom' for the third array", () => {
+		expect(sevenBoom([2, 55, 60, 97, 86])).toEqual("Boom!");
+	});
+
+	it("should return three 'Boom' for the fourth array", () => {
+		expect(sevenBoom([7, 77, 100])).toEqual("Boom! Boom! Boom!");
+	});
+});

Problems/Seven-Boom/solver.ts

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+export default function sevenBoom(array: number[]): string {
+	const sevenCount = array
+		.join("")
+		.split("")
+		.reduce((count, current) => (current === "7" ? count + 1 : count), 0);
+
+	if (sevenCount === 0) return "there is no 7 in the array";
+	else return "Boom! ".repeat(sevenCount).trim();
+}

README.md

@@ -8,9 +8,9 @@ This repository is about solving coding-problems. It contains famous (or not tha
 
 ## Problems
 
-Solved: **25 problems**
+Solved: **26 problems**
 
-🟢 Easy: 19  
+🟢 Easy: 20  
 🟠 Medium: 5  
 🔴 Hard: 1
 
@@ -41,6 +41,7 @@ Solved: **25 problems**
 | [Remove the last vowel](./Problems/Remove-The-Last-Vowel/README.md)                     | 🟢 Easy    |
 | [Bingo Check](./Problems/Bingo-Check/README.md)                                         | 🟢 Easy    |
 | [Missing Number](./Problems/Missing-Number/README.md)                                   | 🟢 Easy    |
+| [Seven Boom!](./Problems/Seven-Boom/README.md)                                          | 🟢 Easy    |
 
 <!-- PROBLEMS_END -->