Given a binary tree, find its minimum depth.
The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.
/**
* Definition for binary tree
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public int minDepth(TreeNode root) {
if(root == null)
return 0;
return depthOfTree(root);
}
public int depthOfTree(TreeNode root){
if(root.left == null && root.right == null){//叶子节点
return 1;
}
int left = 0;
if(root.left != null)
left = depthOfTree(root.left);
int right = 0;
if(root.right != null)
right = depthOfTree(root.right);
if(left != 0 && right != 0)
return 1 + (left < right ? left : right);
else if(left != 0)
return 1 + left;
else
return 1 + right;
}
}
跟求树的最大深度的思想一样
Runtime: 257 ms