072. Max Sum Contiguous Subarray.py

# Max sum Contiguous subarray
"""
Find the contiguous subarray within an array, A of length N which has the largest sum.

Input Format:

The first and the only argument contains an integer array, A.
Output Format:

Return an integer representing the maximum possible sum of the contiguous subarray.
Constraints:

1 <= N <= 1e6
-1000 <= A[i] <= 1000
For example:

Input 1:
    A = [1, 2, 3, 4, -10]

Output 1:
    10

Explanation 1:
    The subarray [1, 2, 3, 4] has the maximum possible sum of 10.

Input 2:
    A = [-2, 1, -3, 4, -1, 2, 1, -5, 4]

Output 2:
    6

Explanation 2:
    The subarray [4,-1,2,1] has the maximum possible sum of 6.
"""
class Solution:
    # @param A : tuple of integers
    # @return an integer
    def maxSubArray(self, A):
        maxsum = cursum = A[0]
        for a in A[1:]:
            cursum = max(cursum + a, a)
            maxsum = max(cursum, maxsum)
        return maxsum