From 2e4c2cc72b81ac2268f3c4211833506e083ebaff Mon Sep 17 00:00:00 2001
From: Hiro Funatsuka <hiro.funatsuka@gmail.com>
Date: Sat, 2 May 2026 00:06:09 +0900
Subject: [PATCH] Solve move zeroes

---
 283_move_zeroes/.DS_Store  | Bin 0 -> 6148 bytes
 283_move_zeroes/problem.md |   1 +
 283_move_zeroes/step1.md   |  29 +++++++++++++++++++++
 283_move_zeroes/step2.md   |  50 +++++++++++++++++++++++++++++++++++++
 283_move_zeroes/step3.md   |  19 ++++++++++++++
 5 files changed, 99 insertions(+)
 create mode 100644 283_move_zeroes/.DS_Store
 create mode 100644 283_move_zeroes/problem.md
 create mode 100644 283_move_zeroes/step1.md
 create mode 100644 283_move_zeroes/step2.md
 create mode 100644 283_move_zeroes/step3.md

diff --git a/283_move_zeroes/.DS_Store b/283_move_zeroes/.DS_Store
new file mode 100644
index 0000000000000000000000000000000000000000..5008ddfcf53c02e82d7eee2e57c38e5672ef89f6
GIT binary patch
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literal 0
HcmV?d00001

diff --git a/283_move_zeroes/problem.md b/283_move_zeroes/problem.md
new file mode 100644
index 0000000..4d37c3a
--- /dev/null
+++ b/283_move_zeroes/problem.md
@@ -0,0 +1 @@
+## 問題: [283. Move Zeroes](https://leetcode.com/problems/move-zeroes/description/)
diff --git a/283_move_zeroes/step1.md b/283_move_zeroes/step1.md
new file mode 100644
index 0000000..f8ea5a5
--- /dev/null
+++ b/283_move_zeroes/step1.md
@@ -0,0 +1,29 @@
+# Step 1
+
+- 0を探すポインタと0以外を探すポインタを使う
+- 0に遭遇したら、そのインデックスの1つ先から0以外を探す
+- 0以外を見つけたら、その値と前述で見つけた0を入れ替える
+
+```python
+class Solution:
+    def moveZeroes(self, nums: List[int]) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        l, r = 0, 1
+        while l < len(nums) and r < len(nums):
+            if nums[l] != 0:
+                l += 1
+                continue
+            r = l + 1
+            while r < len(nums):
+                if nums[r] == 0:
+                    r += 1
+                else:
+                    nums[l], nums[r] = nums[r], nums[l]
+                    break
+```
+
+時間計算量: O(n^2)
+
+空間計算量: O(1)
diff --git a/283_move_zeroes/step2.md b/283_move_zeroes/step2.md
new file mode 100644
index 0000000..0f81525
--- /dev/null
+++ b/283_move_zeroes/step2.md
@@ -0,0 +1,50 @@
+# Step 2
+
+- Step 1のコードは遅い
+- rのインデックスを毎回lの1個先にリセットしないようにしたい
+
+```python
+class Solution:
+    def moveZeroes(self, nums: List[int]) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        l, r = 0, 0
+        while l < len(nums) and r < len(nums):
+            if nums[l] != 0:
+                l += 1
+                r = max(r, l)
+                continue
+            while r < len(nums):
+                if nums[r] == 0:
+                    r += 1
+                else:
+                    nums[l], nums[r] = nums[r], nums[l]
+                    break
+
+```
+
+時間計算量: $O(n)$
+
+空間計算量: $O(1)$
+
+- 他の人のコード見たらもっとスマートなのがあった
+- 0でない値が次にどのインデックスに来るか変数で持つ
+- 変数は0で始まり、0でない値がみつかったら、変数が示すインデックスに格納されている値と入れ替える
+
+```python
+class Solution:
+    def moveZeroes(self, nums: List[int]) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        non_zero_index = 0
+        for i in range(len(nums)):
+            if nums[i] != 0:
+                nums[i], nums[non_zero_index] = nums[non_zero_index], nums[i]
+                zero_index += 1
+
+```
+時間計算量: $O(n)$
+
+空間計算量: $O(1)$
\ No newline at end of file
diff --git a/283_move_zeroes/step3.md b/283_move_zeroes/step3.md
new file mode 100644
index 0000000..1fe7c86
--- /dev/null
+++ b/283_move_zeroes/step3.md
@@ -0,0 +1,19 @@
+# Step 3
+
+```python
+class Solution:
+    def moveZeroes(self, nums: List[int]) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        non_zero_index = 0
+        for i in range(len(nums)):
+            if nums[i] != 0:
+                nums[i], nums[non_zero_index] = nums[non_zero_index], nums[i]
+                zero_index += 1
+```
+1回目: 1分　9秒
+
+2回目: 1分　2秒
+
+3回目: 0分　56秒