Create clone_graph.cpp

Author: avidLearnerInProgress

clone_graph.cpp

@@ -0,0 +1,38 @@
+/*
+// Definition for a Node.
+class Node {
+public:
+    int val;
+    vector<Node*> neighbors;
+    Node() {
+        val = 0;
+        neighbors = vector<Node*>();
+    }
+    Node(int _val) {
+        val = _val;
+        neighbors = vector<Node*>();
+    }
+    Node(int _val, vector<Node*> _neighbors) {
+        val = _val;
+        neighbors = _neighbors;
+    }
+};
+*/
+
+class Solution {
+public:
+    unordered_map<Node*, Node*> map;
+    Node* cloneGraph(Node* node) {
+        if (node == NULL) return NULL;
+        return dfs(node);
+    }
+    
+    Node* dfs(Node* node) {
+        if (map.find(node) != map.end()) return map[node];
+        Node* clone = new Node(node->val);
+        map[node] = clone; // map OLD node to NEW node!
+        for (Node* n : node->neighbors)
+            clone->neighbors.push_back(dfs(n));
+        return clone;
+    }
+};