From cb57b7ffe0c002b085f05e258f196f93d19de8ae Mon Sep 17 00:00:00 2001
From: JungHm <taggma12@gmail.com>
Date: Wed, 30 Apr 2025 13:29:47 +0900
Subject: [PATCH 1/2] solve: best time to buy and sell stock

---
 best-time-to-buy-and-sell-stock/JustHm.swift | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 best-time-to-buy-and-sell-stock/JustHm.swift

diff --git a/best-time-to-buy-and-sell-stock/JustHm.swift b/best-time-to-buy-and-sell-stock/JustHm.swift
new file mode 100644
index 000000000..5e2705017
--- /dev/null
+++ b/best-time-to-buy-and-sell-stock/JustHm.swift
@@ -0,0 +1,17 @@
+// time: O(n) space: O(n)
+class Solution {
+    func maxProfit(_ prices: [Int]) -> Int {
+        guard !prices.isEmpty else { return 0 }
+        var result = [Int]()
+        var current = prices[0]
+
+        for price in prices {
+            if current > price {
+                current = price
+                continue
+            }
+            result.append(price - current)
+        }
+        return result.max() ?? 0
+    }
+}

From 9c12f7c6a7eb6d9df156e0d3c58a470526270528 Mon Sep 17 00:00:00 2001
From: JungHm <taggma12@gmail.com>
Date: Fri, 2 May 2025 21:12:28 +0900
Subject: [PATCH 2/2] solve: implement trie prefix tree

---
 implement-trie-prefix-tree/JustHm.swift | 35 +++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 implement-trie-prefix-tree/JustHm.swift

diff --git a/implement-trie-prefix-tree/JustHm.swift b/implement-trie-prefix-tree/JustHm.swift
new file mode 100644
index 000000000..034805fbf
--- /dev/null
+++ b/implement-trie-prefix-tree/JustHm.swift
@@ -0,0 +1,35 @@
+
+class Trie {
+    var children: [Character: Trie] = [:]
+    var isEndOfWord = false
+
+    func insert(_ word: String) {
+        guard !word.isEmpty else { return }
+        var node = self
+        for char in word {
+            if node.children[char] == nil {
+                node.children[char] = Trie()
+            }
+            node = node.children[char]!
+        }
+        node.isEndOfWord = true
+    }
+
+    func search(_ word: String) -> Bool {
+        guard let node = findNode(word) else { return false }
+        return node.isEndOfWord
+    }
+
+    func startsWith(_ prefix: String) -> Bool {
+        return findNode(prefix) != nil
+    }
+
+    private func findNode(_ word: String) -> Trie? {
+        var node = self
+        for char in word {
+            guard let next = node.children[char] else { return nil }
+            node = next
+        }
+        return node
+    }
+}