feat(solutions): add maximum-subarray-sum/python/linear

challenges/maximum-subarray-sum/solutions/python/linear/README.md

@@ -0,0 +1,3 @@
+# maximum-subarray-sum/python/linear
+
+Created by [@Divlo](https://github.com/Divlo) on 1 May 2022.

challenges/maximum-subarray-sum/solutions/python/linear/solution.py

@@ -0,0 +1,26 @@
+import sys
+
+
+def maximum_subarray_sum_linear(array: list[int]) -> int:
+    """
+    Time complexity: O(array_length)
+
+    We loop through the array and for each array position, we calculate the maximum sum of a subarray that ends at that position. After this, the answer for the problem is the maximum of those sums.
+    """
+    if len(array) == 0:
+        return 0
+    best_sum = array[0]
+    length = len(array)
+    sum = 0
+    for i in range(length):
+        sum = max(array[i], sum + array[i])
+        best_sum = max(best_sum, sum)
+    return best_sum
+
+
+numbers: list[int] = []
+for value in sys.stdin:
+    numbers.append(int(value.rstrip('\n')))
+
+numbers = numbers[1:]
+print(maximum_subarray_sum_linear(numbers))