Create: 133-Clone-Graph.ts

Author: andra961

Diff for: typescript/133-Clone-Graph.ts

@@ -0,0 +1,26 @@
+let dfs = (node: Node, memo: Map<Node, Node>) => {
+    if (node === null) return null;
+
+    //if this node has already been visited, simply return the counterpart node of the new graph and return
+    if (memo.has(node)) return memo.get(node);
+
+    //node hasn't been already visited, create its counterpart version for the new graph
+    let newNode = new Node(node.val);
+    //maps to the old graph counterpart(also marked as visited)
+    memo.set(node, newNode);
+
+    //for each edge of the old node, add that edge in the new graph node
+    for (let i = 0; i < node.neighbors.length; i++) {
+        newNode.neighbors.push(dfs(node.neighbors[i], memo));
+    }
+
+    return newNode;
+};
+
+function cloneGraph(node: Node | null): Node | null {
+    //uses a map, maps old graph nodes with new graph ones
+    //it also tells us which node of the old graph have already been visited
+    let memo = new Map<Node, Node>();
+
+    return dfs(node, memo);
+}