938. Range Sum of BST

[twy30]

https://leetcode.com/problems/range-sum-of-bst/

using System;
using System.Collections.Generic;

public class Solution
{
    public int RangeSumBST(TreeNode root, int low, int high)
    {
        // 「根節點」
        var rootNode = root;

        // 「下限值」（含）
        var inclusiveLowerBound = low;

        // 「上限值」（含）
        var inclusiveUpperBound = high;

        // 「節點佇列」
        var nodeQueue = new Queue<TreeNode>();

        // 「輸出值」
        var output = 0;

        nodeQueue.Enqueue(rootNode);

        // 「節點」
        TreeNode node;

        while (nodeQueue.TryDequeue(out node))
        {
            if (node == null) { continue; }

            // 「節點的數值」
            var nodeValue = node.val;

            if (inclusiveLowerBound <= nodeValue && nodeValue <= inclusiveUpperBound)
            {
                output += nodeValue;
            }

            nodeQueue.Enqueue(node.left);
            nodeQueue.Enqueue(node.right);
        }

        return output;
    }
}

參考資料

上限、下限

https://en.wikipedia.org/wiki/Upper_and_lower_bounds

• 上限： upper bound 或 majorant
• 下限： lower bound 或 minorant

包含、不含

• inclusive
  • https://www.lexico.com/en/definition/inclusive
• exclusive
  • https://www.lexico.com/en/definition/exclusive

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請參考「刷 LeetCode 練習命名」 https://github.com/EngTW/English-for-Programmers/issues/69 😊