Merge pull request #3763 from drxlx/0228-summary-ranges

Create 0228-summary-ranges.swift

Author: Ykhan799

Diff for: swift/0228-summary-ranges.swift

@@ -0,0 +1,27 @@
+class Solution {
+    func summaryRanges(_ nums: [Int]) -> [String] {
+        if nums.isEmpty {
+            return []
+        }
+        var l = 0
+        var res = [String]()
+        for r in 1..<nums.count {
+            if nums[r] != nums[r - 1] + 1 { 
+                if l == r - 1 {
+                    res.append("\(nums[l])")
+                } else {
+                    res.append("\(nums[l])->\(nums[r - 1])")
+                }
+                l = r
+            } 
+        }
+
+        if l == nums.count - 1 {
+            res.append("\(nums[l])")
+        } else {
+            res.append("\(nums[l])->\(nums[nums.count - 1])")
+        }
+
+        return res
+    }
+}