Package g0101_0200.s0133_clone_graph

Class Solution

  • public class Solution
extends Object
    133 - Clone Graph.

    Medium

    Given a reference of a node in a connected undirected graph.

    Return a deep copy (clone) of the graph.

    Each node in the graph contains a value (int) and a list (List[Node]) of its neighbors.

    class Node { public int val; public List<Node> neighbors; }

    Test case format:

    For simplicity, each node’s value is the same as the node’s index (1-indexed). For example, the first node with val == 1, the second node with val == 2, and so on. The graph is represented in the test case using an adjacency list.

    An adjacency list is a collection of unordered lists used to represent a finite graph. Each list describes the set of neighbors of a node in the graph.

    The given node will always be the first node with val = 1. You must return the copy of the given node as a reference to the cloned graph.

    Example 1:

    Input: adjList = [[2,4],[1,3],[2,4],[1,3]]

    Output: [[2,4],[1,3],[2,4],[1,3]]

    Explanation:

     There are 4 nodes in the graph.
 1st node (val = 1)'s neighbors are 2nd node (val = 2) and 4th node (val = 4).
 2nd node (val = 2)'s neighbors are 1st node (val = 1) and 3rd node (val = 3).
 3rd node (val = 3)'s neighbors are 2nd node (val = 2) and 4th node (val = 4).
 4th node (val = 4)'s neighbors are 1st node (val = 1) and 3rd node (val = 3).

    Example 2:

    Input: adjList = [[]]

    Output: [ []]

    Explanation: Note that the input contains one empty list. The graph consists of only one node with val = 1 and it does not have any neighbors.

    Example 3:

    Input: adjList = []

    Output: []

    Explanation: This an empty graph, it does not have any nodes.

    Example 4:

    Input: adjList = [[2],[1]]

    Output: [[2],[1]]

    Constraints:

    • The number of nodes in the graph is in the range [0, 100].
    • 1 <= Node.val <= 100
    • Node.val is unique for each node.
    • There are no repeated edges and no self-loops in the graph.
    • The Graph is connected and all nodes can be visited starting from the given node.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • cloneGraph

        public Node cloneGraph​(Node node)