[leetcode]Minimum Depth of Binary Tree-java広さ遍歴
1531 ワード
/**
* 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;
}
LinkedList<TreeNode> queue = new LinkedList<TreeNode>();
LinkedList<TreeNode> childQueue = new LinkedList<TreeNode>();
queue.add(root);
int depth = 1;
while (!queue.isEmpty()){
TreeNode node = queue.remove();
if(node.left==null && node.right==null){
return depth;
}
if(node.left!=null){
childQueue.add(node.left);
}
if(node.right!=null){
childQueue.add(node.right);
}
if(queue.isEmpty() && !childQueue.isEmpty()){
depth++;
queue.addAll(childQueue);
childQueue.clear();
}
}
return depth;
}
}