643. Maximum Average Subarray I 最大子阵列平均数

Posted 2020-09-28 Long Long Journey

Given an array consisting of n integers, find the contiguous subarray of given length k that has the maximum average value. And you need to output the maximum average value.

Example 1:

Input: [1,12,-5,-6,50,3], k = 4Output: 12.75Explanation: Maximum average is (12-5-6+50)/4 = 51/4 = 12.75

Note:

1. 1 <= k <= n <= 30,000.

2. Elements of the given array will be in the range [-10,000, 10,000].

 题意：求一个数组的最大子阵列平均数

 思路：运用动态规划，找出和最大，长度为k的子阵列

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class Solution(object):     def findMaxAverage(self, nums, k):         """         :type nums: List[int]         :type k: int         :rtype: float         """         sum = 0         curSum = 0         addNum = 0         for i in range(0, len(nums)):             if addNum < k:                 curSum += nums[i]                 sum = curSum                 addNum += 1             else:                 curSum = curSum - nums[i - k] + nums[i]                 sum = max(sum, curSum)         return sum * 1.0 / k

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