题目:
Given a binary tree, find its minimum depth.
The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.
题意求到叶子节点最短的距离。
递归遍历,注意必须要到叶子节点,中间的节点不能算。
/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int minDepth(TreeNode *root) { if(!root)return 0; int a=minDepth(root->right); int b=minDepth(root->left); if(a*b!=0)return min(a,b)+1; else if(b==0)return a+1; else if(a==0) return b+1; } };