py.py

def max_subarray_cost(arr):
    if not arr:
        return 0
    
    max_sum = arr[0]
    current_sum = arr[0]
    
    for num in arr[1:]:
        current_sum = max(num, current_sum + num)
        max_sum = max(max_sum, current_sum)
    
    return max_sum ** 2

# Test cases
arr1 = [1, -1, 1, -1, 1]
arr2 = [1, 2, 3]
arr3 = [-2, -3, -1, -5]
arr4 = [0, 0, 0, 0]
arr5 = [-2, 1, -3, 4, -1, 2, 1, -5, 4]

print(max_subarray_cost(arr1))  # Output: 1
print(max_subarray_cost(arr2))  # Output: 36
print(max_subarray_cost(arr3))  # Output: 1
print(max_subarray_cost(arr4))  # Output: 0
print(max_subarray_cost(arr5))  # Output: 16