LeetCode - 111. Minimum Depth of Binary Tree

题目

LeetCode - 111. Minimum Depth of Binary Tree

题目链接

https://leetcode.com/problems/minimum-depth-of-binary-tree/

参考博客

解题思路

带层参数的深度优先遍历。

解题源码

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    
    int minlevel = INT_MAX;
    void dfs(TreeNode* root, int level){
        if(root){
            if(root->left == nullptr && root->right == nullptr)
                minlevel = min(minlevel, level);
            dfs(root->left, level + 1);
            dfs(root->right, level + 1);
        }
    }
    
    int minDepth(TreeNode* root) {
        dfs(root, 1);
        if (minlevel == INT_MAX) return 0;
        else return minlevel;
    }
};