feat(2023): add solution for challenge #17

2023/challenge-17/README.md

@@ -0,0 +1,31 @@
+# Challenge #17: Optimizing the rental
+
+In Rovaniemi, Finland 🇫🇮, sleds 🛷 are rented by time intervals. **Each interval is represented as an array of two elements**, where the first element is the start of the rental and the second one is the end.
+
+For example, the array `[2, 7]` represents a rental that begins at hour `2` and ends at hour `7`. The problem is that sometimes the intervals overlap with each other, making it confusing to figure out from what time to what time the sled was rented.
+
+We're asked to, in order to simplify the task of calculating the total rental time, **write a function that merges all overlapping intervals** and **returns an array of sorted intervals**:
+
+```js
+optimizeIntervals([
+  [5, 8],
+  [2, 7],
+  [3, 4],
+]) // [[2, 8]]
+
+optimizeIntervals([
+  [1, 3],
+  [8, 10],
+  [2, 6],
+]) // [[1, 6], [8, 10]]
+
+optimizeIntervals([
+  [3, 4],
+  [1, 2],
+  [5, 6],
+]) // [[1, 2], [3, 4], [5, 6]]
+```
+
+You can assume that **the first element of each interval is always less than or equal to the second element**. But **the intervals are not necessarily sorted.**
+
+The hour numbers can go up to the figure `9999`.

2023/challenge-17/challenge-17.test.ts

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+import { describe } from 'vitest'
+import { optimizeIntervals } from './challenge-17'
+
+const TEST_CASES: TestCases<
+  Array<[number, number]>,
+  Array<[number, number]>
+> = [
+  {
+    args: [
+      [2, 7],
+      [3, 4],
+      [5, 8],
+    ],
+    expected: [[2, 8]],
+  },
+  {
+    args: [
+      [3, 4],
+      [5, 8],
+      [2, 7],
+    ],
+    expected: [[2, 8]],
+  },
+  {
+    args: [
+      [1, 3],
+      [2, 6],
+      [8, 10],
+    ],
+    expected: [
+      [1, 6],
+      [8, 10],
+    ],
+  },
+  {
+    args: [
+      [1, 2],
+      [3, 4],
+      [5, 6],
+    ],
+    expected: [
+      [1, 2],
+      [3, 4],
+      [5, 6],
+    ],
+  },
+  {
+    args: [
+      [5, 7],
+      [6, 8],
+    ],
+    expected: [[5, 8]],
+  },
+  {
+    args: [
+      [1, 5],
+      [6, 10],
+      [11, 15],
+      [16, 20],
+    ],
+    expected: [
+      [1, 5],
+      [6, 10],
+      [11, 15],
+      [16, 20],
+    ],
+  },
+  {
+    args: [
+      [1, 15],
+      [8, 12],
+      [4, 7],
+    ],
+    expected: [[1, 15]],
+  },
+]
+
+describe('Challenge #17: Optimizing the rental', () => {
+  buildChallengeTestCases({
+    cases: TEST_CASES,
+    fn: optimizeIntervals,
+  })
+})

2023/challenge-17/challenge-17.ts

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+export function optimizeIntervals(intervals: Array<[number, number]>) {
+  intervals.sort((a, b) => a[0] - b[0])
+
+  const result = [intervals[0]]
+
+  for (const currentInterval of intervals) {
+    const lastMergedInterval = result[result.length - 1]
+
+    if (currentInterval[0] <= lastMergedInterval[1]) {
+      lastMergedInterval[1] = Math.max(
+        lastMergedInterval[1],
+        currentInterval[1],
+      )
+    } else {
+      result.push(currentInterval)
+    }
+  }
+
+  return result
+}

README.md

@@ -105,7 +105,7 @@ This repository contains the solutions to the challenges proposed by [@midudev](
 | 14  |        Avoid the alarm         |       🟠       | [Show](https://adventjs.dev/challenges/2023/14) | [Go](./2023/challenge-14/challenge-14.ts) |
 | 15  |        Autonomous robot        |       🟠       | [Show](https://adventjs.dev/challenges/2023/15) | [Go](./2023/challenge-15/challenge-15.ts) |
 | 16  |       Friday deployment        |       🟢       | [Show](https://adventjs.dev/challenges/2023/16) | [Go](./2023/challenge-16/challenge-16.ts) |
-| 17  |               --               |       --       |                       --                        |                    --                     |
+| 17  |     Optimizing the rental      |       🟢       | [Show](https://adventjs.dev/challenges/2023/17) | [Go](./2023/challenge-17/challenge-17.ts) |
 | 18  |               --               |       --       |                       --                        |                    --                     |
 | 19  |               --               |       --       |                       --                        |                    --                     |
 | 20  |               --               |       --       |                       --                        |                    --                     |