二叉树深度
import java.util.Queue;
import java.util.LinkedList;
/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val) {
this.val = val;
}
}
*/
public class Solution {
/**
递归方法求二叉树的深度
**/
public int TreeDepth(TreeNode root) {
if(root == null) return 0;
int left = TreeDepth(root.left);
int right = TreeDepth(root.right);
return Math.max(left,right) + 1;
}
//非递归算法
public int treeDepth(TreeNode root){
if(root == null) return 0;
Queue<TreeNode> queue = new LinkedList<TreeNode>();
int level = 0,count = 0,nextCount = 1;
queue.add(root);
while(!queue.isEmpty()){
TreeNode top = queue.poll();
if(top.left != null) queue.add(top.left);
if(top.right != null) queue.add(top.right);
count++;
if(count == nextCount){
nextCount = queue.size();
count = 0;
level++;
}
}
return level;
}
}