Maxium circular subarray sum

break_it_down

• Base condition if array size is one return the first value.
• Initialize sum variable to 0.
• Iterate the array and update sum variable to contain sum of array elements.

Code

 
class Solution {
    //Function to find maximum circular subarray sum.
    circularSubarraySum(a, N){
    // Corner Case
           if (N == 1)
               return a[0];
 
           // Initialize sum variable which store total sum of the array.
           let sum = 0;
           for (let i = 0; i < N; i++) {
               sum += a[i];
           }
 
           // Initialize every variable with first value of array.
           let curr_max = a[0], max_so_far = a[0], curr_min = a[0], min_so_far = a[0];
 
           // Concept of Kadane's Algorithm
           for (let i = 1; i < N; i++) {
               // Kadane's Algorithm to find Maximum subarray sum.
               curr_max = Math.max(curr_max + a[i], a[i]);
               max_so_far = Math.max(max_so_far, curr_max);
 
               // Kadane's Algorithm to find Minimum subarray sum.
               curr_min = Math.min(curr_min + a[i], a[i]);
               min_so_far = Math.min(min_so_far, curr_min);
           }
 
           if (min_so_far == sum)
               return max_so_far;
 
           // returning the maximum value
           return Math.max(max_so_far, sum - min_so_far);
    } 
}