Maximum Sum Circular Subarray LeetCode solution in Java

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class Solution {
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  public int maxSubarraySumCircular(int[] nums) {
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    int ans = kadane(nums);
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    int sum = 0;
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    for (int i = 0; i < nums.length; i++) {
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      sum += nums[i];
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      nums[i] = -nums[i];
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    }
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    int kadane_sum = kadane(nums) + sum;
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    if (kadane_sum == 0) {
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      return ans;
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    }
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    return Math.max(ans, kadane_sum);
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  }
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  public int kadane(int[] nums) {
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    int sum = 0;
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    int ans = Integer.MIN_VALUE;
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    for (int i : nums) {
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      sum += i;
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      ans = Math.max(ans, sum);
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      if (sum < 0) {
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        sum = 0;
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      }
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    }
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    return ans;
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  }
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}