[C#][LeetCode][Easy] 104. Maximum Depth of Binary Tree

心得:

這題是典型的遞迴題目,題目要求找到二元樹最深的層級為多少。

這題的解法很簡單,先宣告兩個變數分別來儲存左邊與右邊的層級,首先判斷左邊是否為空,若非為空值則會繼續搜尋此節點的子節點是否為空,搜尋完畢後再一併回傳至第一層的left變數裡,右邊反之,最後在比較左右兩邊哪個最大,最大的數字即為二元樹的層級。

問題:

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.
答案:

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/**
* Definition for a binary tree node.
* public class TreeNode {
* public int val;
* public TreeNode left;
* public TreeNode right;
* public TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public int MaxDepth(TreeNode root) {
if (root == null)
{
return 0;
}

int left = 1;
int right = 1;

if (root.left != null)
{
left += MaxDepth(root.left);
}

if (root.right != null)
{
right += MaxDepth(root.right);
}

return right > left ? right : left;
}
}

參考:

  1. https://skyyen999.gitbooks.io/-leetcode-with-javascript/content/questions/104md.html