package basic.graph;

import java.util.HashSet;
import java.util.Stack;

/**
 * 图的深度优先遍历
 * <p>
 * 微信公众号:Java和算法学习
 *
 * @author 周一
 */
public class DFS {

 public static void dfs(Node node) {
 if (node == null) {
 return;
 }
 Stack<Node> stack = new Stack<>();
 HashSet<Node> set = new HashSet<>();
 Node current = node;
 stack.add(current);
 set.add(current);
 // 入栈就打印
 System.out.println(current.value);

 while (!stack.isEmpty()) {
 current = stack.pop();
 for (Node next : current.nexts) {
 if (!set.contains(next)) {
 stack.add(current);
 stack.add(next);
 set.add(next);
 System.out.println(next.value);
 // 只入栈一个Set中不包含的节点
 break;
 }
 }
 }
 }

}