From 09b75dc610378c8dd12cc868afbb75093a603d2e Mon Sep 17 00:00:00 2001
From: choidabom <dabomi0305@naver.com>
Date: Mon, 6 Jan 2025 11:28:04 +0900
Subject: [PATCH 1/4] feat: 121. Best Time to Buy and Sell Stock

---
 best-time-to-buy-and-sell-stock/choidabom.ts | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 best-time-to-buy-and-sell-stock/choidabom.ts

diff --git a/best-time-to-buy-and-sell-stock/choidabom.ts b/best-time-to-buy-and-sell-stock/choidabom.ts
new file mode 100644
index 000000000..f7f08d589
--- /dev/null
+++ b/best-time-to-buy-and-sell-stock/choidabom.ts
@@ -0,0 +1,20 @@
+/**
+ * Runtime: 6ms, Memory: 62.30MB
+ *
+ * Time Complexity: O(N)
+ * Space Complexity: O(1)
+ */
+
+function maxProfit(prices: number[]): number {
+  let buyingPrice = prices[0];
+  let profit = 0;
+
+  for (const price of prices) {
+    buyingPrice = Math.min(price, buyingPrice);
+    profit = Math.max(profit, price - buyingPrice);
+  }
+
+  return profit;
+}
+
+maxProfit([7, 1, 5, 3, 6, 4]);

From bb30d81ec6f182f0359b5fd66afcb8bf22489282 Mon Sep 17 00:00:00 2001
From: choidabom <dabomi0305@naver.com>
Date: Tue, 7 Jan 2025 12:43:29 +0900
Subject: [PATCH 2/4] add: problem link

---
 best-time-to-buy-and-sell-stock/choidabom.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/best-time-to-buy-and-sell-stock/choidabom.ts b/best-time-to-buy-and-sell-stock/choidabom.ts
index f7f08d589..42b4a7abe 100644
--- a/best-time-to-buy-and-sell-stock/choidabom.ts
+++ b/best-time-to-buy-and-sell-stock/choidabom.ts
@@ -1,4 +1,5 @@
 /**
+ * https://leetcode.com/problems/best-time-to-buy-and-sell-stock/description/
  * Runtime: 6ms, Memory: 62.30MB
  *
  * Time Complexity: O(N)

From ad8a118f1801c73d29cfbe265e797f1890be3acd Mon Sep 17 00:00:00 2001
From: choidabom <dabomi0305@naver.com>
Date: Tue, 7 Jan 2025 12:46:55 +0900
Subject: [PATCH 3/4] feat: 49. Group Anagrams

---
 group-anagrams/choidabom.ts | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 group-anagrams/choidabom.ts

diff --git a/group-anagrams/choidabom.ts b/group-anagrams/choidabom.ts
new file mode 100644
index 000000000..6cb2507b8
--- /dev/null
+++ b/group-anagrams/choidabom.ts
@@ -0,0 +1,32 @@
+/**
+ * https://leetcode.com/problems/group-anagrams/description/
+ * Runtime: 27ms, Memory: 64.26MB
+ *
+ * Time Complexity: O(n * m * log m)
+ * Space Complexity: O(n * m)
+ *
+ * 접근
+ * anagrams 관계인 단어는 정렬 시 모두 동일한 단어가 된다.
+ * 그러므로 정렬된 단어가 key 값이 되고, str을 정렬했을 때 key값과 동일한 경우 value가 되도록 추가.
+ */
+
+function groupAnagrams(strs: string[]): string[][] {
+  let answer = [];
+  const anagramMap = new Map<string, string[]>();
+
+  for (let str of strs) {
+    const key = str.split("").sort().join(""); // O(m * log m)
+    if (!anagramMap.has(key)) {
+      anagramMap.set(key, []);
+    }
+    anagramMap.get(key)?.push(str);
+  }
+
+  anagramMap.forEach((value) => {
+    answer.push(value);
+  });
+
+  return answer;
+}
+
+groupAnagrams(["eat", "tea", "tan", "ate", "nat", "bat"]);

From efdefa1e6c5197a9af0a1a8b408cc5917cd7f756 Mon Sep 17 00:00:00 2001
From: choidabom <dabomi0305@naver.com>
Date: Wed, 8 Jan 2025 23:17:43 +0900
Subject: [PATCH 4/4] feat: Encode and Decode Strings

---
 encode-and-decode-strings/choidabom.ts | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 encode-and-decode-strings/choidabom.ts

diff --git a/encode-and-decode-strings/choidabom.ts b/encode-and-decode-strings/choidabom.ts
new file mode 100644
index 000000000..02b1850ab
--- /dev/null
+++ b/encode-and-decode-strings/choidabom.ts
@@ -0,0 +1,19 @@
+/**
+ * https://www.lintcode.com/problem/659/
+ * Time Complexity: O(n)
+ * Space Complexity: O(n)
+ */
+
+function encode(strs: string[]): string {
+  return strs.join("😀");
+}
+
+function decode(str: string): string[] {
+  return str.split("😀");
+}
+
+decode(encode(["Hello", "World"]));
+/*
+ * output
+ * ["Hello","World"]
+ */