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Maximum Sub-array

Problem Statement​

Given an integer array nums, find the subarray which has the largest sum and return its sum.

Leetcode Link

Example 1:​

Input: nums = [-2,1,-3,4,-1,2,1,-5,4]
Output: 6
Explanation: [4,-1,2,1] has the largest sum = 6.

Example 2:​

Input: nums = [1]
Output: 1

Example 3:​

Input: nums = [5,4,-1,7,8]
Output: 23

Constraints:​

  • 1 <= nums.length <= 105
  • -104 <= nums[i] <= 104

Code​

Python Code

class Solution:
    # @param A, a list of integers
    # @return an integer
    # 6:57
    def maxSubArray(self, A):
        if not A:
            return 0

        curSum = maxSum = A[0]
        for num in A[1:]:
            curSum = max(num, curSum + num)
            maxSum = max(maxSum, curSum)

        return maxSum