From f565fc27888e926a2c0c2032c7cb3d78aa2e3f74 Mon Sep 17 00:00:00 2001
From: Rytxxx <k.ryuto.5@icloud.com>
Date: Sun, 30 Nov 2025 18:42:42 -0800
Subject: [PATCH] 033-search-in-rotated-array

---
 033-search-in-rotated-array/memo.md  | 18 ++++++++++++++++++
 033-search-in-rotated-array/step1.py | 16 ++++++++++++++++
 033-search-in-rotated-array/step2.py | 24 ++++++++++++++++++++++++
 033-search-in-rotated-array/step3.py | 21 +++++++++++++++++++++
 4 files changed, 79 insertions(+)
 create mode 100644 033-search-in-rotated-array/memo.md
 create mode 100644 033-search-in-rotated-array/step1.py
 create mode 100644 033-search-in-rotated-array/step2.py
 create mode 100644 033-search-in-rotated-array/step3.py

diff --git a/033-search-in-rotated-array/memo.md b/033-search-in-rotated-array/memo.md
new file mode 100644
index 0000000..066cf75
--- /dev/null
+++ b/033-search-in-rotated-array/memo.md
@@ -0,0 +1,18 @@
+## step1で考えたこと
+
+前回の問題と似たように、L,R,Mを使って、幅を狭めていく、Targetと一致すればその地点のIndexをreturn
+なければ return -1
+ただ、今回のArrayもrotateされているから、シンプルに、nums[mid]とtargetを比較しても
+分割したパーテーションに対象の値がなく、もう一方の方に存在する時にどうIndexを動かしていけば良いかがわからない。
+
+## step2
+Step1としては、
+「左半分 or 右半分のどっちかは必ず昇順」
+「昇順側に target が入っているか範囲で見る」
+という発想に到達できるとベストだった。
+
+なぜ、普通の二分探索の方法が使えないのかを分析した上で、
+左、右のどちらかはソートされていることに気づけていれば正解に近づけた気がする。
+
+elif nums[mid] > nums[left]:
+-> "="のつけ忘れ
\ No newline at end of file
diff --git a/033-search-in-rotated-array/step1.py b/033-search-in-rotated-array/step1.py
new file mode 100644
index 0000000..55f0701
--- /dev/null
+++ b/033-search-in-rotated-array/step1.py
@@ -0,0 +1,16 @@
+class Solution:
+    def search(self, nums: List[int], target: int) -> int:
+        left = 0
+        right = len(nums) - 1
+
+        while left < right:
+            mid = (left + right) // 2
+
+            if nums[mid] == target:
+                return mid
+            elif nums[mid] > target:
+
+            else:
+                
+
+        return -1
\ No newline at end of file
diff --git a/033-search-in-rotated-array/step2.py b/033-search-in-rotated-array/step2.py
new file mode 100644
index 0000000..503d2f0
--- /dev/null
+++ b/033-search-in-rotated-array/step2.py
@@ -0,0 +1,24 @@
+## 解答解説を見た後に自力で書いたコード
+
+class Solution:
+    def search(self, nums: List[int], target: int) -> int:
+        left = 0
+        right = len(nums) - 1
+
+        while left <= right:
+            mid = (left + right) // 2
+
+            if nums[mid] == target:
+                return mid
+            elif nums[mid] > nums[left]:
+                if nums[left] <= target < nums[mid]:
+                    right = mid - 1
+                else:
+                    left = mid + 1
+            else:
+                if nums[mid] < target <= nums[right]:
+                    left = mid + 1
+                else:
+                    right = mid - 1
+
+        return -1
diff --git a/033-search-in-rotated-array/step3.py b/033-search-in-rotated-array/step3.py
new file mode 100644
index 0000000..04cd581
--- /dev/null
+++ b/033-search-in-rotated-array/step3.py
@@ -0,0 +1,21 @@
+class Solution:
+    def search(self, nums: List[int], target: int) -> int:
+        left = 0
+        right = len(nums) - 1
+
+        while left <= right:
+            mid = (left + right) // 2
+
+            if nums[mid] == target:
+                return mid
+            elif nums[left] <= nums[mid]:
+                if nums[left] <= target < nums[mid]:
+                    right = mid - 1
+                else:
+                    left = mid + 1
+            else:
+                if nums[mid] < target <= nums[right]:
+                    left = mid + 1
+                else:
+                    right = mid - 1
+        return -1