题目
给定一个二叉树，找出其最小深度。
二叉树的最小深度为根节点到最近叶子节点的距离。
代码
/**
* Definition of TreeNode:
* public class TreeNode {
* public int val;
* public TreeNode left, right;
* public TreeNode(int val) {
* this.val = val;
* this.left = this.right = null;
* }
* }
*/
public class Solution {
/**
* @param root: The root of binary tree.
* @return: An integer.
*/
public int minDepth(TreeNode root) {
// write your code here
if (root == null) {
return 0;
}
return getMin(root);
}
public int getMin(TreeNode root){
if (root == null) {
return Integer.MAX_VALUE;
}
if (root.left == null && root.right == null) {
return 1;
}
return Math.min(getMin(root.left), getMin(root.right)) + 1;
}
}
/**
* Definition of TreeNode:
* public class TreeNode {
* public int val;
* public TreeNode left, right;
* public TreeNode(int val) {
* this.val = val;
* this.left = this.right = null;
* }
* }
*/
public class Solution {
/**
* @param root: The root of binary tree.
* @return: An integer.
*/
public int minDepth(TreeNode root) {
if(null == root) return 0;
if(null == root.left) return minDepth(root.right) + 1;
if(null == root.right) return minDepth(root.left) + 1;
return Math.min(minDepth(root.left),minDepth(root.right)) + 1;
}
}
