Steward

分享是一種喜悅、更是一種幸福

程式語言 - LeetCode - C++ - 530. Minimum Absolute Difference in BST

---

題目：


解答：

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    int getMinimumDifference(TreeNode* root) {
        int ans = INT_MAX;
        TreeNode *pre = nullptr;

        auto dfs = [&](this auto&& dfs, TreeNode *n) {
            if (!n) {
                return;
            }

            dfs(n->left);

            if (pre) {
                ans = min(ans, n->val - pre->val);
            }
            pre = n;

            dfs(n->right);
        };

        dfs(root);

        return ans;
    }
};