leetCode No.53 Maximum Subarray

题目

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.

For example, given the array [-2,1,-3,4,-1,2,1,-5,4],
the contiguous subarray [4,-1,2,1] has the largest sum = 6.

标签：Array、Dynamic Programming、Divide and Conquer
相似问题: (E) Best Time to Buy and Sell Stock、(M) Maximum Product Subarray

题意

在给定的数组中找到相加和最大的子串，子串大小最小为1。

解题思路

从头开始累加，如果当前的和为正数则可以继续累加，若为负数，继续相加结果必然较下一个单独数小。又因为必须是连续子串所以要抛弃之前的和，从当前值从新开始。

代码

class Solution(object):
    def maxSubArray(self, nums):
        """ :type nums: List[int] :rtype: int """
        m_sum = 0
        max_sum = -2147483648
        for i in nums:
            if m_sum >= 0:
                m_sum += i
            else:
                m_sum = i
            if m_sum > max_sum:
                max_sum = m_sum
        return max_sum

相关链接

源代码（github）
原题