0280-wiggle-sort

0280-wiggle-sort.playground/Contents.swift

@@ -0,0 +1,27 @@
+/// 280. Wiggle Sort
+/// Given an unsorted array nums, reorder it in-place such that
+/// nums[0] <= nums[1] >= nums[2] <= nums[3]....
+
+import XCTest
+
+/// Approach: Swap
+func wiggleSort(_ nums: inout [Int]) {
+    guard nums.count > 1 else { return }
+    for i in 0..<nums.count - 1 {
+        if (i % 2 == 0 && nums[i] > nums[i + 1]) ||
+           (i % 2 != 0 && nums[i] < nums[i + 1]) {
+            nums.swapAt(i, i + 1)
+        }
+    }
+}
+
+class Tests: XCTestCase {
+    func testExample() {
+        var nums = [3, 5, 2, 1, 6, 4]
+        let expected = [3, 5, 1, 6, 2, 4]
+        wiggleSort(&nums)
+        XCTAssertEqual(nums, expected)
+    }
+}
+
+Tests.defaultTestSuite.run()

0280-wiggle-sort.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='macos' executeOnSourceChanges='false'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

README.md

@@ -57,6 +57,7 @@ You can visit the pages below to search problems by company tags. Then come back
 163 | [Missing Ranges](https://leetcode.com/problems/missing-ranges/description/) | [Solution](https://github.com/zhubofei/LeetCode-Swift/blob/master/0163-missing-ranges.playground/Contents.swift) | Iteration
 200 | [Number of Islands](https://leetcode.com/problems/number-of-islands/description/) | [Solution](https://github.com/zhubofei/LeetCode-Swift/blob/master/0200-number-of-islands.playground/Contents.swift) | BFS
 259 | [Three Sum Smaller](https://leetcode.com/problems/3sum-smaller/description/) | [Solution](https://github.com/zhubofei/LeetCode-Swift/blob/master/0259-3sum-smaller.playground/Contents.swift) | Two Pointers
+280 | [Wiggle Sort](https://leetcode.com/problems/wiggle-sort/description/) | [Solution](https://github.com/zhubofei/LeetCode-Swift/blob/master/0280-wiggle-sort.playground/Contents.swift) | Swap
 482 | [License Key Formatting](https://leetcode.com/problems/license-key-formatting/description/) | [Solution](https://github.com/zhubofei/LeetCode-Swift/blob/master/0482-license-key-formatting.playground/Contents.swift) | String
 681 | [Next Closest Time](https://leetcode.com/problems/next-closest-time/description/) | [Solution](https://github.com/zhubofei/LeetCode-Swift/blob/master/0681-next-closest-time.playground/Contents.swift) | Simulation
 683 | [K Empty Slots](https://leetcode.com/problems/k-empty-slots/description/) | [Solution](https://github.com/zhubofei/LeetCode-Swift/blob/master/0683-k-empty-slots.playground/Contents.swift) | Sliding Window