From 4c4eb212c5cd2e33e3d00095aa36bdbb99f7f9be Mon Sep 17 00:00:00 2001
From: jinah92 <jinah0818@gmail.com>
Date: Mon, 6 Jan 2025 15:48:58 +0900
Subject: [PATCH 1/3] =?UTF-8?q?feat:=20week5=20=EB=AC=B8=EC=A0=9C=ED=92=80?=
 =?UTF-8?q?=EC=9D=B4(221,=20236,=20238)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 best-time-to-buy-and-sell-stock/jinah92.py | 13 ++++++++++++
 encode-and-decode-strings/jinah92.py       | 24 ++++++++++++++++++++++
 group-anagrams/jinah92.py                  | 24 ++++++++++++++++++++++
 3 files changed, 61 insertions(+)
 create mode 100644 best-time-to-buy-and-sell-stock/jinah92.py
 create mode 100644 encode-and-decode-strings/jinah92.py
 create mode 100644 group-anagrams/jinah92.py

diff --git a/best-time-to-buy-and-sell-stock/jinah92.py b/best-time-to-buy-and-sell-stock/jinah92.py
new file mode 100644
index 000000000..b5c2cf0c9
--- /dev/null
+++ b/best-time-to-buy-and-sell-stock/jinah92.py
@@ -0,0 +1,13 @@
+# O(N) times, O(1) spaces
+# price[i] 가격으로 팔아서 가장 수익을 많이 내려면, i-1번째까지 중 가장 값이 싼 날짜에서 주식을 사면 된다
+class Solution:
+    def maxProfit(self, prices: List[int]) -> int:
+        max_profit = 0
+        min_price = prices[0]
+
+        for price in prices:
+            profit = price - min_price
+            max_profit = max(max_profit, profit)
+            min_price = min(min_price, price)
+        
+        return max_profit
diff --git a/encode-and-decode-strings/jinah92.py b/encode-and-decode-strings/jinah92.py
new file mode 100644
index 000000000..c97ab01be
--- /dev/null
+++ b/encode-and-decode-strings/jinah92.py
@@ -0,0 +1,24 @@
+# O(N) times, O(1) spaces
+class Solution:
+    """
+    @param: strs: a list of strings
+    @return: encodes a list of strings to a single string.
+    """
+    def encode(self, strs):
+        encoded_str = ""
+        for str in strs:
+            encoded_str += f"{len(str)}:{str}"
+        return encoded_str
+
+    """
+    @param: str: A string
+    @return: decodes a single string to a list of strings
+    """
+    def decode(self, str):
+        list_strs, start = [], 0
+        while start < len(str):
+            offset = str.find(":", start)
+            s_length = int(str[start:offset])
+            list_strs.append(str[offset+1:offset+1+s_length])
+            start = offset+1+s_length
+        return list_strs
diff --git a/group-anagrams/jinah92.py b/group-anagrams/jinah92.py
new file mode 100644
index 000000000..2a93854fc
--- /dev/null
+++ b/group-anagrams/jinah92.py
@@ -0,0 +1,24 @@
+# O(N * NlogN) times, O(N) spaces
+class Solution:
+    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
+        anagrams_dict = {}
+        result = []
+
+        for str in strs: # N 시간 소요
+            str_count = {}
+            for s in str:
+                if not s in str_count:
+                    str_count[s] = 1
+                else:
+                    str_count[s] += 1
+            anagrams_keys = []
+            for key, val in sorted(str_count.items()): # 최대 N개의 dict items를 배열하므로 NlogN 시간 소요
+                anagrams_keys.append(tuple([key, val]))
+        
+            anagrams_key = tuple(anagrams_keys)
+            if tuple(anagrams_keys) not in anagrams_dict:
+                anagrams_dict[tuple(anagrams_keys)] = []
+            anagrams_dict[tuple(anagrams_keys)].append(str)
+
+
+        return list(anagrams_dict.values())

From d6d458e3a0b43c16c1594f52efce28d6fe85d92f Mon Sep 17 00:00:00 2001
From: jinah92 <jinah0818@gmail.com>
Date: Thu, 9 Jan 2025 14:40:10 +0900
Subject: [PATCH 2/3] =?UTF-8?q?feat:=20wwek5=20=EB=AC=B8=EC=A0=9C=ED=92=80?=
 =?UTF-8?q?=EC=9D=B4=20(256)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 implement-trie-prefix-tree/jinah92.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 implement-trie-prefix-tree/jinah92.py

diff --git a/implement-trie-prefix-tree/jinah92.py b/implement-trie-prefix-tree/jinah92.py
new file mode 100644
index 000000000..e675748e7
--- /dev/null
+++ b/implement-trie-prefix-tree/jinah92.py
@@ -0,0 +1,16 @@
+# 시간복잡도
+## insert, search는 해시 기반 조회로 인해 O(1), startsWith은 O(n * k) 시간이 소요 (n: 저장된 단어수, k: prefix 길이)
+# 공간복잡도
+## O(n * m) 공간이 필요 (n: 저장된 단어 수, m : 각 단어의 평균 길이)
+class Trie:
+    def __init__(self):
+        self.trie = set()
+    
+    def insert(self, word: str) -> None:
+        self.trie.add(word)
+
+    def search(self, word: str) -> bool:
+        return word in self.trie
+
+    def startsWith(self, prefix: str) -> bool:
+        return any(item.startswith(prefix) for item in self.trie)

From f5abbbe87e625a0f4003a725906520d7fc062029 Mon Sep 17 00:00:00 2001
From: jinah92 <jinah0818@gmail.com>
Date: Fri, 10 Jan 2025 13:51:46 +0900
Subject: [PATCH 3/3] =?UTF-8?q?feat:=20week5=20=EB=AC=B8=EC=A0=9C=ED=92=80?=
 =?UTF-8?q?=EC=9D=B4=20(271)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 word-break/jinah92.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 word-break/jinah92.py

diff --git a/word-break/jinah92.py b/word-break/jinah92.py
new file mode 100644
index 000000000..17765f924
--- /dev/null
+++ b/word-break/jinah92.py
@@ -0,0 +1,14 @@
+# O(2^s*w) times, O(s) space
+class Solution:
+    def wordBreak(self, s: str, wordDict: List[str]) -> bool:
+        @cache
+        def dfs(start):
+            if start == len(s):
+                return True
+            for word in wordDict:
+                if s[start:start+len(word)] == word:
+                    if dfs(start+len(word)):
+                        return True
+            return False
+        
+        return dfs(0)