Minimum Depth of Binary Tree

Maximum Depth of Binary Tree

可以这样写

1 int maxDepth(TreeNode *root) {
2         if(!root)
3             return 0;
4         else
5             return 1+max(maxDepth(root->left),maxDepth(root->right));
6     }

如果仿照上面

1 int minDepth(TreeNode *root) {
2         if(!root)
3             return 0;
4         else
5             return 1+min(minDepth(root->left),minDepth(root->right));
6     }

Status: Wrong Answer

Input:	{1,2}
Output:	1
Expected:	2

根据这个错误的提示，需要加上两个判断

1 if(!(root->right)&&root->left)
2             return 1+minDepth(root->left);
3         else if(!(root->left)&&root->right)
4             return 1+minDepth(root->right);

AC 完整代码：

 1 /**
 2  * Definition for binary tree
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     int minDepth(TreeNode *root) {
13         if(!root)
14             return 0;
15         if(!(root->right)&&root->left)
16             return 1+minDepth(root->left);
17         else if(!(root->left)&&root->right)
18             return 1+minDepth(root->right);
19         else
20             return 1+min(minDepth(root->left),minDepth(root->right));
21     }
22 };

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