链接:https://www.nowcoder.com/questionTerminal/435fb86331474282a3499955f0a41e8b?f=discussion
来源:牛客网
二叉树的深度
非递归写法:层次遍历
import java.util.Queue; import java.util.LinkedList; public class Solution { public int TreeDepth(TreeNode pRoot) { if(pRoot == null){ return 0; } Queue<TreeNode> queue = new LinkedList<TreeNode>(); queue.add(pRoot); int depth = 0, count = 0, nextCount = 1; while(queue.size()!=0){ TreeNode top = queue.poll(); count++; if(top.left != null){ queue.add(top.left); } if(top.right != null){ queue.add(top.right); } if(count == nextCount){ nextCount = queue.size(); count = 0; depth++; } } return depth; } }
递归写法:
import java.lang.Math; public class Solution { public int TreeDepth(TreeNode pRoot) { if(pRoot == null){ return 0; } int left = TreeDepth(pRoot.left); int right = TreeDepth(pRoot.right); return Math.max(left, right) + 1; } }