题解 | #二叉树的最大深度# | Rust

/**
 * #[derive(PartialEq, Eq, Debug, Clone)]
 * pub struct TreeNode {
 *     pub val: i32,
 *     pub left: Option<Box<TreeNode>>,
 *     pub right: Option<Box<TreeNode>>,
 * }
 *
 * impl TreeNode {
 *     #[inline]
 *     fn new(val: i32) -> Self {
 *         TreeNode {
 *             val: val,
 *             left: None,
 *             right: None,
 *         }
 *     }
 * }
 */
struct Solution{

}

impl Solution {
    fn new() -> Self {
        Solution{}
    }

    /**
    * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
    *
    * 
        * @param root TreeNode类 
        * @return int整型
    */
    pub fn maxDepth(&self, root: Option<Box<TreeNode>>) -> i32 {
        // write code here
        if root.is_none() {
            return 0;
        }
        let left = Solution::maxDepth(self, root.as_ref().unwrap().left.clone());
        let right = Solution::maxDepth(self, root.as_ref().unwrap().right.clone());
        return 1 + std::cmp::max(left, right);
    }
}