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.
题解:注意没有的分支不算。
/** * 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 dfs(TreeNode *r){ if(r==NULL) return 0; if(r->left==NULL&&r->right==NULL){ return 1; } else{ if(r->left==NULL){ return dfs(r->right)+1; } else if(r->right==NULL){ return dfs(r->left)+1; } else{ return min(dfs(r->left),dfs(r->right)) + 1; } } } int minDepth(TreeNode* root) { return dfs(root); } };