feat: Add solution for LeetCode problem 133

Author: WhiteHyun

clone-graph/WhiteHyun.swift

@@ -0,0 +1,41 @@
+//  
+//  133. Clone Graph
+//  https://leetcode.com/problems/clone-graph/description/
+//  Dale-Study
+//  
+//  Created by WhiteHyun on 2024/06/28.
+//  
+
+/**
+ * Definition for a Node.
+ * public class Node {
+ *     public var val: Int
+ *     public var neighbors: [Node?]
+ *     public init(_ val: Int) {
+ *         self.val = val
+ *         self.neighbors = []
+ *     }
+ * }
+ */
+
+class Solution {
+  var cache: [Int: Node] = [:]
+
+  func cloneGraph(_ originalNode: Node?) -> Node? {
+    guard let originalNode
+    else {
+      return nil
+    }
+
+    guard cache[originalNode.val] == nil
+    else { return cache[originalNode.val]! }
+
+    let node = Node(originalNode.val)
+    cache[originalNode.val] = node
+
+
+    node.neighbors = originalNode.neighbors.map(cloneGraph)
+
+    return node
+  }
+}