LeetCode 270: Closest Binary Search Tree Value

最新推荐文章于 2022-01-16 02:58:50 发布

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本文介绍了如何在一个非空的二叉搜索树中找到与给定目标值最接近的值。利用二叉搜索树的特性，通过递归的方式遍历树节点，计算每个节点值与目标值之间的绝对距离，并更新最接近的目标值。

BST. Left node value < root value < right node value.

/*
  Given a non-empty binary search tree and a target value, find the value in BST
  that is closest to the target.
  Note:
  1: Given target value is a floating point.
  2: You are guranteed to have only one unique value in BST that is closest to the target.
*/

// Because it is BST, we are going to use the BST feature.
int closestValue(TreeNode* root, double target) {
  int minDistance = INT_MAX;
  int tmp = root->val;
  while(root) {
    int distance = abs(root->val - target);
    if(distance < minDistance) {
      minDistance = distance;
      tmp = root->val;
    }
    if(root->val > target) root = root->left;
    else if(root->val < target) root = root->right;
    else return root->val;
  }
  return tmp;
}