树:
题目描述:
求给定二叉树的最小深度。最小深度是指树的根结点到最近叶子结点的最短路径上结点的数量。
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.
输入描述:
输出描述:
示例1:
输入:
输出:
代码:
import java.util.LinkedList;
import java.util.Queue;
public class Solution {
public int run(TreeNode root) {
if(root == null)
return 0;
if(root.left == null && root.right == null)
return 1;
int depth = 0;
Queue<TreeNode> queue = new LinkedList<>();
queue.offer(root);
while(!queue.isEmpty()){
int len = queue.size();
depth++;
for(int i = 0; i < len; i++){
TreeNode cur = queue.poll();
if(cur.left == null && cur.right == null)
return depth;
if(cur.left != null)
queue.offer(cur.left);
if(cur.right != null)
queue.offer(cur.right);
}
}
return 0;
}
}