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Maximum subarray sum in an array created after repeated concatenation | Returns sum of maximum sum subarray created after concatenating a [ 0. . n - 1 ] k times ..
This is where it differs from Kadane 's  algorithm. We use  modular arithmetic to  find next element..
Driver program to test maxSubArraySum"
Solution in Python:

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What is a code to maximum subarray sum in an array created after repeated concatenation and the other steps required?
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#Here is code to maximum subarray sum in an array created after repeated concatenation and the other steps required.
 def maxSubArraySumRepeated ( a , n , k ) :
	max_so_far = - 2147483648
	max_ending_here = 0
	for i in range ( n * k ) :
		max_ending_here = max_ending_here + a [ i % n ]
		if ( max_so_far < max_ending_here ) :
			max_so_far = max_ending_here
		if ( max_ending_here < 0 ) :
			max_ending_here = 0
	return max_so_far
a = [ 10 , 20 , - 30 , - 1 ]
n = len ( a )
k = 3
print ( " Maximum ▁ contiguous ▁ sum ▁ is ▁ " , maxSubArraySumRepeated ( a , n , k ) )