Maximum Subarray II - [ 数据结构与算法/leetcode/lintcode题解 ]
Given an array of integers, find two non-overlapping subarrays which have the largest sum. The number in each subarray should be contiguous. Return the largest sum. Example For given [1, 3, -1, 2, -1, 2], the two subarrays are [1, 3] and [2, -1, 2] or [1, 3, -1, 2] and [2], they both have the largest sum 7. Note The subarray should contain at least one number Challenge Can you do it in time complexity O(n) ?题解
严格来讲这道题这道题也可以不用动规来做，这里还是采用经典的动规解法。Maximum Subarray 中要求的是数组中最大子数组和，这里是求不相重叠的两个子数组和的和最大值，做过买卖股票系列的题的话这道题就非常容易了，既然我们已经求出了单一子数组的最大和，那么我们使用隔板法将数组一分为二，分别求这两段的最大子数组和，求相加后的最大值即为最终结果。隔板前半部分的最大子数组和很容易求得，但是后半部分难道需要将索引从0开始依次计算吗？NO!!! 我们可以采用从后往前的方式进行遍历，这样时间复杂度就大大降低了。
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