Continuous Subarray Sum

最新推荐文章于 2025-07-29 14:24:32 发布

转载最新推荐文章于 2025-07-29 14:24:32 发布 · 776 阅读

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原文链接：http://www.cnblogs.com/sherylwang/p/5697525.html

Given an integer array, find a continuous subarray where the sum of numbers is the biggest. Your code should return the index of the first number and the index of the last number. (If their are duplicate answer, return anyone)

和Maximum Subarray的差别在于仅仅需要返回index。思路还是求以每个index结束的子数组的最大值，local， global DP。代码如下：

class Solution:
    # @param {int[]} A an integer array
    # @return {int[]}  A list of integers includes the index of the 
    #                  first number and the index of the last number
    def continuousSubarraySum(self, A):
        if not A:
            return [0,0]
        res = [0, 0]
        localMax = 0  #for every index, subarray ended with this index's largest sum
        globalMax = -sys.maxint
        start = 0
        end = 0
        for i in xrange(len(A)):
            if localMax +  A[i] < A[i]:  #localMax < 0, abandon the former subarray
                start = i
                end = i
                localMax = A[i]
            else:
                localMax += A[i]
                end = i
            if localMax > globalMax:
                globalMax = localMax
                res[0] = start
                res[1] = end
        return res

转载于:https://www.cnblogs.com/sherylwang/p/5697525.html