[Search] code style fixed

Author: Yi Gu

Diff for: Search/ClosestBinarySearchTreeValue.swift

@@ -29,18 +29,19 @@ class ClosestBinarySearchTreeValue {
     }
 
     private func _helper(node: TreeNode?, _ target: Double, _ closest: Int) -> Int {
-        if let node = node {
-            var closest = closest
-            if abs(target - Double(node.val)) < abs(target - Double(closest)) {
-                closest = node.val
-            }
-            if Double(node.val) < target {
-                return _helper(node.right, target, closest)
-            } else {
-                return _helper(node.left, target, closest)
-            }
+        guard let node = node else {
+            return closest
+        }
+    
+        var closest = closest
+        if abs(target - Double(node.val)) < abs(target - Double(closest)) {
+            closest = node.val
         }
 
-        return closest
+        if Double(node.val) < target {
+            return _helper(node.right, target, closest)
+        } else {
+            return _helper(node.left, target, closest)
+        }
     }
 }

Diff for: Search/SearchInRotatedSortedArray.swift

@@ -9,9 +9,10 @@ class SearchInRotatedSortedArray {
     func search(nums: [Int], _ target: Int) -> Int {
         var left = 0
         var right = nums.count - 1
+        var mid = 0
 
         while left <= right {
-            var mid = (right - left) / 2 + left
+            mid = (right - left) / 2 + left
 
             if nums[mid] == target {
                 return mid

Diff for: Search/SearchInRotatedSortedArrayII.swift

@@ -9,9 +9,10 @@ class SearchInRotatedSortedArrayII {
     func search(nums: [Int], _ target: Int) -> Bool {
         var left = 0
         var right = nums.count - 1
+        var mid = 0
 
         while left <= right {
-            var mid = (right - left) / 2 + left
+            mid = (right - left) / 2 + left
 
             if nums[mid] == target {
                 return true

Diff for: Search/Sqrtx.swift

@@ -16,9 +16,10 @@ class Sqrtx {
 
         var left = 0
         var right = x / 2 + 1
-        
+        var mid = 0
+
         while left <= right {
-            var mid = (right - left) / 2 + left
+            mid = (right - left) / 2 + left
 
             if mid * mid == x {
                 return mid