class Solution {

int maxSubarraySumCircular(vector<int>& nums) {

const int n = nums.size();

vector<int> suffix(n);

suffix[n - 1] = nums[n - 1];

int suffix_sum = nums[n - 1];

for (int i = n - 2; i >= 0; i--) {

suffix_sum += nums[i];

suffix[i] = max(suffix[i + 1], suffix_sum);

}

int normalSum = nums[0];

int special_sum = nums[0];

int currSum = 0;

int prefixSum = 0;

for (int i = 0; i < n; ++i) {

// Kadane algo start

currSum += nums[i];

normalSum = max(normalSum, currSum);

if(currSum < 0){

currSum = 0;

}

// kadane algo end

prefixSum += nums[i];

if (i + 1 < n) {

special_sum = max(special_sum, prefixSum + suffix[i + 1]);

}

}

return max(normalSum, special_sum);

}

};