From 76faef22ff29c3e7a8ce09cfb5713e46fa0c309f Mon Sep 17 00:00:00 2001
From: juan <juancloudcomputing@protonmail.com>
Date: Sun, 10 Jul 2022 09:57:15 +0800
Subject: [PATCH] vault backup: 2022-07-10 09:57:15

---
 OJ notes/pages/Leetcode Rotate-Array.md | 35 +++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/OJ notes/pages/Leetcode Rotate-Array.md b/OJ notes/pages/Leetcode Rotate-Array.md
index 7a9ecfc..50a1207 100644
--- a/OJ notes/pages/Leetcode Rotate-Array.md	
+++ b/OJ notes/pages/Leetcode Rotate-Array.md	
@@ -58,6 +58,41 @@ rotate 2 steps to the right: [3,99,-1,-100]
 
 #### Method 2: Copy
 
+Watch out for integer overflow.
+
 #### Method 3: CPP's STL
 
+
+
 ### Solution
+
+Method 2:
+```cpp
+class Solution {
+  void swap(vector<int> &nums, int l, int r) {
+    int temp = nums[l];
+    nums[l] = nums[r];
+    nums[r] = temp;
+  }
+
+public:
+  void rotate(vector<int> &nums, int k) {
+    int size = nums.size();
+    if (size <= 1) {
+      return;
+    }
+    // Copy
+    k = size - k;
+    while (k < 0) {
+      k += size;
+    }
+    vector<int> ans(nums.size());
+    for (int i = 0; i < size; i++) {
+      ans[i] = nums[(i + k) % size];
+    }
+    for (int i = 0; i < size; i++) {
+      nums[i] = ans[i];
+    }
+  }
+};
+```
\ No newline at end of file