From cab901c2b4cda6161f720eb5d893a5e3b4ecc743 Mon Sep 17 00:00:00 2001
From: iswilljr <iswilljr@gmail.com>
Date: Fri, 1 Dec 2023 18:11:32 -0500
Subject: [PATCH] feat(2023): add solution for challenge #01

---
 2023/challenge-01/README.md            | 28 ++++++++++++++++++++++++++
 2023/challenge-01/challenge-01.test.ts | 25 +++++++++++++++++++++++
 2023/challenge-01/challenge-01.ts      |  7 +++++++
 README.md                              |  5 +++--
 4 files changed, 63 insertions(+), 2 deletions(-)
 create mode 100644 2023/challenge-01/README.md
 create mode 100644 2023/challenge-01/challenge-01.test.ts
 create mode 100644 2023/challenge-01/challenge-01.ts

diff --git a/2023/challenge-01/README.md b/2023/challenge-01/README.md
new file mode 100644
index 0000000..ef6c97c
--- /dev/null
+++ b/2023/challenge-01/README.md
@@ -0,0 +1,28 @@
+# Challenge #1: First gift repeated!
+
+In the toy factory of the North Pole, each toy has a unique identification number.
+
+However, due to an error in the toy machine, some numbers have been assigned to more than one toy.
+
+Find the first identification number that has been repeated, **where the second occurrence has the smallest index!**
+
+In other words, if there is more than one repeated number, you must return the number whose second occurrence appears first in the list. If there are no repeated numbers, return `-1`.
+
+```js
+const giftIds = [2, 1, 3, 5, 3, 2]
+const firstRepeatedId = findFirstRepeated(giftIds)
+console.log(firstRepeatedId) // 3
+// Even though 2 and 3 are repeated
+// 3 appears second time first
+
+const giftIds2 = [1, 2, 3, 4]
+const firstRepeatedId2 = findFirstRepeated(giftIds2)
+console.log(firstRepeatedId2) // -1
+// It is -1 since no number is repeated
+
+const giftIds3 = [5, 1, 5, 1]
+const firstRepeatedId3 = findFirstRepeated(giftIds3)
+console.log(firstRepeatedId3) // 5
+```
+
+**Watch out!** The elves say this is a Google technical test.
diff --git a/2023/challenge-01/challenge-01.test.ts b/2023/challenge-01/challenge-01.test.ts
new file mode 100644
index 0000000..e927035
--- /dev/null
+++ b/2023/challenge-01/challenge-01.test.ts
@@ -0,0 +1,25 @@
+import { describe } from 'vitest'
+import { findFirstRepeated } from './challenge-01'
+
+const TEST_CASES: TestCases<number[], number> = [
+  {
+    args: [2, 1, 3, 5, 3, 2],
+    expected: 3,
+  },
+  { args: [2, 2], expected: 2 },
+  { args: [2, 4, 3, 5, 1], expected: -1 },
+  { args: [1], expected: -1 },
+  { args: [], expected: -1 },
+  { args: [10, 20, 30], expected: -1 },
+  { args: [5, 1, 2, 3, 2, 5, 1], expected: 2 },
+  { args: [12, 20, 30, 11, 20, 12], expected: 20 },
+  { args: [12, 10, 13, 12, 13], expected: 12 },
+  { args: [0, 10, 13, 0, 13], expected: 0 },
+]
+
+describe('Challenge #1: First gift repeated!', () => {
+  buildChallengeTestCases({
+    cases: TEST_CASES,
+    fn: findFirstRepeated,
+  })
+})
diff --git a/2023/challenge-01/challenge-01.ts b/2023/challenge-01/challenge-01.ts
new file mode 100644
index 0000000..fbaa97d
--- /dev/null
+++ b/2023/challenge-01/challenge-01.ts
@@ -0,0 +1,7 @@
+export function findFirstRepeated(gifts: number[]) {
+  const firstRepeatedGift = gifts.find((gift, index) => {
+    return gifts.indexOf(gift) !== index
+  })
+
+  return firstRepeatedGift ?? -1
+}
diff --git a/README.md b/README.md
index cea4c9b..64b30ea 100644
--- a/README.md
+++ b/README.md
@@ -87,8 +87,9 @@ This repository contains the solutions to the challenges proposed by [@midudev](
 
 ### 🕹️ Challenges
 
-|  #  | Challenge | Difficulty[^1] | Description | Solution |
-| :-: | :-------: | :------------: | :---------: | :------: |
+|  #  |      Challenge       | Difficulty[^1] |                  Description                   |                 Solution                  |
+| :-: | :------------------: | :------------: | :--------------------------------------------: | :---------------------------------------: |
+| 01  | First gift repeated! |       🟢       | [Show](https://adventjs.dev/challenges/2023/1) | [Go](./2023/challenge-01/challenge-01.ts) |
 
 </details>