// Source : https://leetcode.com/problems/clone-graph/

// Author : Han Zichi

// Date : 2016-08-28

/**

* Definition for undirected graph.

* function UndirectedGraphNode(label) {

* this.label = label;

* this.neighbors = []; // Array of UndirectedGraphNode

* }

*/

/**

* @param {UndirectedGraphNode} graph

* @return {UndirectedGraphNode}

*/

var cloneGraph = function(graph) {

if (!graph)

return null;

var hash = {};

return dfs(graph);

function dfs(node) {

var label = node.label;

var newNode = new UndirectedGraphNode(label);

hash[label] = newNode;

for (var i = 0, len = node.neighbors.length; i < len; i++) {

var item = node.neighbors[i];

if (hash[item.label] !== undefined)

newNode.neighbors.push(hash[item.label]);

else

newNode.neighbors.push(dfs(item));

}

return newNode;

}

};