參考上一題求深度，記得如果有一邊是null，就要返回另一邊的深度+1?。?！這個不能夠省略，否則就wa
/** * 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 minDepth(TreeNode* root) { if(root == NULL) return 0; if(root -> left == NULL && root -> right == NULL) return 1; int dl = minDepth(root -> left); int dr = minDepth(root -> right); if(dl == 0) return dr + 1; if(dr == 0) return dl + 1; return dl > dr ? dr + 1: dl + 1; }};新聞熱點
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