618. Search Graph Nodes

Description

Given a undirected graph, a node and a target, return the nearest node to given node which value of it is target, return NULL if you can't find.

There is a mapping store the nodes' values in the given parameters.

It's guaranteed there is only one available solution

Example

Example 1:

Input:

{1,2,3,4#2,1,3#3,1#4,1,5#5,4}

[3,4,5,50,50]

1

50

Output:

4

Explanation:

2------3  5

\    |  |

  \    |  |

  \  |  |

    \  |  |

      1 --4

Give a node 1, target is 50

there a hash named values which is [3,4,10,50,50], represent:

Value of node 1 is 3

Value of node 2 is 4

Value of node 3 is 10

Value of node 4 is 50

Value of node 5 is 50

Return node 4

Example 2:

Input:

{1,2#2,1}

[0,1]

1

1

Output:

2

思路：

类似最短路径，用BFS就可以，因为题目中已经给定一个hashmap，所以可以直接利用该hashmap存储节点的访问信息，不需要自己再建立一个。另外序列化的无向图代表的是每个起点的连边信息，如1,2,3,4代表顶点1与2， 3， 4分别相连。

代码：