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Commit 913a54b

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feat: add solutions to lc problem: No.0918. Maximum Sum Circular Subaray
1 parent 6d6f012 commit 913a54b

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‎README.md‎

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- [跳跃游戏](./solution/0000-0099/0055.Jump%20Game/README.md)
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- [跳跃游戏 II](./solution/0000-0099/0045.Jump%20Game%20II/README.md)
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- [最大子序和](./solution/0000-0099/0053.Maximum%20Subarray/README.md)
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- [环形子数组的最大和](./solution/0900-0999/0918.Maximum%20Sum%20Circular%20Subarray/README.md)
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- [接雨水](./solution/0000-0099/0042.Trapping%20Rain%20Water/README.md)
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- [礼物的最大价值](./lcof/面试题47.%20礼物的最大价值/README.md)
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- [最小路径和](./solution/0000-0099/0064.Minimum%20Path%20Sum/README.md)

‎README_EN.md‎

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@@ -162,6 +162,7 @@ Complete solutions to [LeetCode](https://leetcode.com/problemset/all/), [LCOF](h
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- [Jump Game](./solution/0000-0099/0055.Jump%20Game/README_EN.md)
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- [Jump Game II](./solution/0000-0099/0045.Jump%20Game%20II/README_EN.md)
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- [Maximum Subarray](./solution/0000-0099/0053.Maximum%20Subarray/README_EN.md)
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- [Maximum Sum Circular Subarray](./solution/0900-0999/0918.Maximum%20Sum%20Circular%20Subarray/README_EN.md)
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- [Trapping Rain Water](./solution/0000-0099/0042.Trapping%20Rain%20Water/README_EN.md)
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- [Minimum Path Sum](./solution/0000-0099/0064.Minimum%20Path%20Sum/README_EN.md)
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- [Decode Ways](./solution/0000-0099/0091.Decode%20Ways/README_EN.md)

‎solution/0900-0999/0918.Maximum Sum Circular Subarray/README.md‎

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<li><code>1 &lt;= A.length &lt;= 30000</code></li>
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</ol>
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## 解法
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<!-- 这里可写通用的实现逻辑 -->
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环形子数组的最大和,可分为两种情况:无环最大和、有环最大和。求其较大值即可。
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无环最大和 s1 的求解可参考:[53. 最大子序和](/solution/0000-0099/0053.Maximum%20Subarray/README.md)。
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对于有环最大和,我们可以转换为求最小子序和 s2,然后用 sum 减去最小子序和,得到有环的最大和。
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注意:若数组所有元素均不大于 0,直接返回无环最大和 s1 即可。
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<!-- tabs:start -->
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### **Python3**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```python
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class Solution:
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def maxSubarraySumCircular(self, nums: List[int]) -> int:
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s1 = s2 = f1 = f2 = nums[0]
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for num in nums[1:]:
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f1 = num + max(f1, 0)
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f2 = num + min(f2, 0)
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s1 = max(s1, f1)
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s2 = min(s2, f2)
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return s1 if s1 <= 0 else max(s1, sum(nums) - s2)
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```
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### **Java**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```java
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class Solution {
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public int maxSubarraySumCircular(int[] nums) {
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int s1 = nums[0], s2 = nums[0], f1 = nums[0], f2 = nums[0], total = nums[0];
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for (int i = 1; i < nums.length; ++i) {
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total += nums[i];
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f1 = nums[i] + Math.max(f1, 0);
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f2 = nums[i] + Math.min(f2, 0);
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s1 = Math.max(s1, f1);
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s2 = Math.min(s2, f2);
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}
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return s1 > 0 ? Math.max(s1, total - s2) : s1;
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}
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}
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```
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### **C++**
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```cpp
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class Solution {
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public:
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int maxSubarraySumCircular(vector<int>& nums) {
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int s1 = nums[0], s2 = nums[0], f1 = nums[0], f2 = nums[0], total = nums[0];
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for (int i = 1; i < nums.size(); ++i) {
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total += nums[i];
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f1 = nums[i] + max(f1, 0);
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f2 = nums[i] + min(f2, 0);
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s1 = max(s1, f1);
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s2 = min(s2, f2);
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}
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return s1 > 0 ? max(s1, total - s2) : s1;
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}
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};
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```
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### **Go**
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```go
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func maxSubarraySumCircular(nums []int) int {
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s1, s2, f1, f2, total := nums[0], nums[0], nums[0], nums[0], nums[0]
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for i := 1; i < len(nums); i++ {
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total += nums[i]
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f1 = nums[i] + max(f1, 0)
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f2 = nums[i] + min(f2, 0)
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s1 = max(s1, f1)
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s2 = min(s2, f2)
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}
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if s1 <= 0 {
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return s1
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}
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return max(s1, total-s2)
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}
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func max(a, b int) int {
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if a > b {
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return a
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}
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return b
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}
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func min(a, b int) int {
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if a < b {
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return a
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}
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return b
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}
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```
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### **...**

‎solution/0900-0999/0918.Maximum Sum Circular Subarray/README_EN.md‎

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### **Python3**
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```python
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class Solution:
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def maxSubarraySumCircular(self, nums: List[int]) -> int:
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s1 = s2 = f1 = f2 = nums[0]
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for num in nums[1:]:
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f1 = num + max(f1, 0)
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f2 = num + min(f2, 0)
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s1 = max(s1, f1)
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s2 = min(s2, f2)
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return s1 if s1 <= 0 else max(s1, sum(nums) - s2)
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```
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### **Java**
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```java
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class Solution {
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public int maxSubarraySumCircular(int[] nums) {
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int s1 = nums[0], s2 = nums[0], f1 = nums[0], f2 = nums[0], total = nums[0];
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for (int i = 1; i < nums.length; ++i) {
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total += nums[i];
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f1 = nums[i] + Math.max(f1, 0);
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f2 = nums[i] + Math.min(f2, 0);
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s1 = Math.max(s1, f1);
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s2 = Math.min(s2, f2);
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}
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return s1 > 0 ? Math.max(s1, total - s2) : s1;
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}
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}
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```
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### **C++**
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```cpp
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class Solution {
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public:
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int maxSubarraySumCircular(vector<int>& nums) {
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int s1 = nums[0], s2 = nums[0], f1 = nums[0], f2 = nums[0], total = nums[0];
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for (int i = 1; i < nums.size(); ++i) {
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total += nums[i];
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f1 = nums[i] + max(f1, 0);
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f2 = nums[i] + min(f2, 0);
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s1 = max(s1, f1);
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s2 = min(s2, f2);
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}
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return s1 > 0 ? max(s1, total - s2) : s1;
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}
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};
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```
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### **Go**
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```go
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func maxSubarraySumCircular(nums []int) int {
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s1, s2, f1, f2, total := nums[0], nums[0], nums[0], nums[0], nums[0]
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for i := 1; i < len(nums); i++ {
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total += nums[i]
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f1 = nums[i] + max(f1, 0)
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f2 = nums[i] + min(f2, 0)
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s1 = max(s1, f1)
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s2 = min(s2, f2)
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}
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if s1 <= 0 {
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return s1
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}
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return max(s1, total-s2)
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}
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func max(a, b int) int {
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if a > b {
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return a
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}
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return b
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}
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func min(a, b int) int {
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if a < b {
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return a
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}
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return b
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}
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```
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### **...**
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class Solution {
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public:
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int maxSubarraySumCircular(vector<int>& nums) {
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int s1 = nums[0], s2 = nums[0], f1 = nums[0], f2 = nums[0], total = nums[0];
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for (int i = 1; i < nums.size(); ++i) {
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total += nums[i];
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f1 = nums[i] + max(f1, 0);
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f2 = nums[i] + min(f2, 0);
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s1 = max(s1, f1);
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s2 = min(s2, f2);
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}
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return s1 > 0 ? max(s1, total - s2) : s1;
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}
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};
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func maxSubarraySumCircular(nums []int) int {
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s1, s2, f1, f2, total := nums[0], nums[0], nums[0], nums[0], nums[0]
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for i := 1; i < len(nums); i++ {
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total += nums[i]
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f1 = nums[i] + max(f1, 0)
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f2 = nums[i] + min(f2, 0)
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s1 = max(s1, f1)
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s2 = min(s2, f2)
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}
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if s1 <= 0 {
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return s1
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}
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return max(s1, total-s2)
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}
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func max(a, b int) int {
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if a > b {
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return a
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}
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return b
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}
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func min(a, b int) int {
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if a < b {
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return a
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}
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return b
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}
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class Solution {
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public int maxSubarraySumCircular(int[] A) {
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int tot = 0;
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int curMax = 0;
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int maxSum = Integer.MIN_VALUE;
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int curMin = 0;
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int minSum = Integer.MAX_VALUE;
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for (int x : A) {
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tot += x;
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curMax = Math.max(curMax + x, x);
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maxSum = Math.max(maxSum, curMax);
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curMin = Math.min(curMin + x, x);
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minSum = Math.min(minSum, curMin);
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public int maxSubarraySumCircular(int[] nums) {
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int s1 = nums[0], s2 = nums[0], f1 = nums[0], f2 = nums[0], total = nums[0];
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for (int i = 1; i < nums.length; ++i) {
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total += nums[i];
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f1 = nums[i] + Math.max(f1, 0);
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f2 = nums[i] + Math.min(f2, 0);
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s1 = Math.max(s1, f1);
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s2 = Math.min(s2, f2);
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}
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return maxSum > 0 ? Math.max(maxSum, tot - minSum) : maxSum;
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return s1 > 0 ? Math.max(s1, total - s2) : s1;
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}
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}
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}
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class Solution:
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def maxSubarraySumCircular(self, nums: List[int]) -> int:
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s1 = s2 = f1 = f2 = nums[0]
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for num in nums[1:]:
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f1 = num + max(f1, 0)
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f2 = num + min(f2, 0)
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s1 = max(s1, f1)
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s2 = min(s2, f2)
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return s1 if s1 <= 0 else max(s1, sum(nums) - s2)

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