hiro111208 · hiro111208 · May 5, 2026 · hemispherium · May 8, 2026
diff --git a/53_maximum_subarray/problem.md b/53_maximum_subarray/problem.md
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+## 問題: [53. Maximum Subarray](https://leetcode.com/problems/maximum-subarray/description/)
diff --git a/53_maximum_subarray/step1.md b/53_maximum_subarray/step1.md
@@ -0,0 +1,20 @@
+# Step 1
+
+- Kadaneのアルゴリズムを使う
+
+```python
+class Solution:
+    def maxSubArray(self, nums: List[int]) -> int:
+        largest_sum = -float('inf')
+        current_sum = 0
+        for num in nums:
+            current_sum = max(current_sum, 0)
+            current_sum += num
+            largest_sum = max(largest_sum, current_sum)
+        return largest_sum
+
+```
+
+時間計算量: $O(n)$
+
+空間計算量: $O(1)$
diff --git a/53_maximum_subarray/step2.md b/53_maximum_subarray/step2.md
@@ -0,0 +1,17 @@
+# Step 2
+
+```python
+class Solution:
+    def maxSubArray(self, nums: List[int]) -> int:
+        largest_sum = -float('inf')
+        current_sum = 0
+        for num in nums:
+            current_sum = max(current_sum, 0) + num
+            largest_sum = max(largest_sum, current_sum)
+        return largest_sum
+
+```
+
+時間計算量: $O(n)$
+
+空間計算量: $O(1)$
diff --git a/53_maximum_subarray/step3.md b/53_maximum_subarray/step3.md
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+# Step 3
+
+```python
+class Solution:
+    def maxSubArray(self, nums: List[int]) -> int:
+        largest_sum = -float('inf')
+        current_sum = 0
+        for num in nums:
+            current_sum = max(current_sum, 0) + num
+            largest_sum = max(largest_sum, current_sum)
+        return largest_sum
+
+```
+
+1回目: 1分　26秒
+
+2回目: 1分　8秒
+
+3回目: 1分　5秒
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		## 問題: [53. Maximum Subarray](https://leetcode.com/problems/maximum-subarray/description/)