【树】783. 二叉搜索树节点最小距离

题目:

 

 

解答：

同题目530。

/**
 * 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:
    void inOrder(TreeNode *root, vector<int> &ret)
    {
        if (NULL == root)
        {
            return;
        }

        inOrder(root->left, ret);
        ret.push_back(root->val);
        inOrder(root->right, ret);
    }

    int minDiffInBST(TreeNode* root) 
    {
        int res = INT_MAX;
        vector<int> ret;
        vector<int> diff;

        inOrder(root, ret);

        for (int i = 1; i < ret.size(); ++i)
        {
            diff.push_back(ret[i] - ret[i-1]);
        }
        for (int i = 0; i < diff.size(); ++i)
        {
            res = std::min(res, diff[i]);
        }

        return res;

    }
};