Function cloneGraph

133-clone-graph/clone-graph.js:15–34

(node)

 * @return {Node}
 */
var cloneGraph = function(node) {
    if (!node) return null;
    
    const visited = new Map();
    
    function dfs(original) {
        if (visited.has(original)) return visited.get(original);
        
        const clone = new Node(original.val);
        visited.set(original, clone);
        
        for (let neighbor of original.neighbors) {
            clone.neighbors.push(dfs(neighbor));
        }
        
        return clone;
    }
    
    return dfs(node);
};