第十五天|104.二叉树的最大深度、111.二叉树的最小深度、 222.完全二叉树的节点个数

104.二叉树的最大深度

题目链接：104. 二叉树的最大深度 - 力扣（LeetCode）

/*** Definition for a binary tree node.* struct TreeNode {*     int val;*     TreeNode *left;*     TreeNode *right;*     TreeNode() : val(0), left(nullptr), right(nullptr) {}*     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}*     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}* };*/
class Solution {
public:int GetDepth(TreeNode* Cur) {if (Cur == nullptr) return 0;int Left = GetDepth(Cur->left);int Right = GetDepth(Cur->right);return 1 + max(Left, Right);}int maxDepth(TreeNode* root) {return GetDepth(root);}
};

111.二叉树的最小深度

题目链接：111. 二叉树的最小深度 - 力扣（LeetCode）

/*** Definition for a binary tree node.* struct TreeNode {*     int val;*     TreeNode *left;*     TreeNode *right;*     TreeNode() : val(0), left(nullptr), right(nullptr) {}*     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}*     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}* };*/
class Solution {
public:int GetMin(TreeNode* Cur) {if (Cur == nullptr) return 0;int left = GetMin(Cur->left);int right = GetMin(Cur->right);if (Cur->left != nullptr && Cur->right == nullptr) return 1 + left;if (Cur->left == nullptr && Cur->right != nullptr) return 1 + right;return 1 + min(left, right);}int minDepth(TreeNode* root) {return GetMin(root);}
};

222.完全二叉树的节点个数

题目链接：222. 完全二叉树的节点个数 - 力扣（LeetCode）

/*** Definition for a binary tree node.* struct TreeNode {*     int val;*     TreeNode *left;*     TreeNode *right;*     TreeNode() : val(0), left(nullptr), right(nullptr) {}*     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}*     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}* };*/
class Solution {
public:int GetCount(TreeNode* Cur) {if (Cur == nullptr) return 0;int left = GetCount(Cur->left);int right = GetCount(Cur->right);return 1 + left + right;}int countNodes(TreeNode* root) {return GetCount(root);}
};