longest_sub_array.py

"""
Author : Yvonne

This is a pure Python implementation of Dynamic Programming solution to the
 longest_sub_array problem.

The problem is :
Given an array, to find the longest and continuous sub array and get the max sum of the
 sub array in the given array.
"""


class SubArray:
 def __init__(self, arr):
 # we need a list not a string, so do something to change the type
 self.array = arr.split(",")

 def solve_sub_array(self):
 rear = [int(self.array[0])] * len(self.array)
 sum_value = [int(self.array[0])] * len(self.array)
 for i in range(1, len(self.array)):
 sum_value[i] = max(
 int(self.array[i]) + sum_value[i - 1], int(self.array[i])
 )
 rear[i] = max(sum_value[i], rear[i - 1])
 return rear[len(self.array) - 1]


if __name__ == "__main__":
 whole_array = input("please input some numbers:")
 array = SubArray(whole_array)
 re = array.solve_sub_array()
 print(("the results is:", re))