LeetCode - 785. Is Graph Bipartite?

判断一个给定图是不是二分图. 题目提供一个用二维数组存储的邻接表. 常规的二分图判断，点着色.

注意要将图存入类中，因为dfs需要访问图中的点.

 1 class Solution {
 2     private int[][] graph;
 3     private boolean[] visited;
 4     private int[] colors;
 5
 6     public boolean isBipartite(int[][] graph) {
 7         this.graph = graph;
 8         int V = graph.length;
 9         visited = new boolean[V];
10         colors = new int[V];
11
12         for (int v = 0; v < V; v++)
13             if (!visited[v])
14                 if(!dfs(v, 0))
15                     return false;
16         return true;
17     }
18
19     private boolean dfs(int v, int color) {
20         visited[v] = true;
21         colors[v] = color;
22         for (int w : graph[v]) {
23             if (!visited[w]) {
24                 if (!dfs(w, 1 - color))
25                     return false;
26             }
27             else if (colors[v] == colors[w])
28                 return false;
29         }
30         return true;
31     }
32 }

原文地址：https://www.cnblogs.com/AntonLiu/p/11288250.html