Leetcode 643. Maximum Average Subarray I (one of the maximum mean Subarray)

Given an arrays consisting n of integers, find the contiguous subarray of Given length that have the k maximum Avera GE 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 would be in the range [-10,000, 10,000].

Title tag: Array

The topic gives us a nums array and a K, let's find a subarray of length k, its average value is the largest.

The easy way to think of this is to sliding window, imagine that there is a windows with a length of k moving, add a new num each time, and subtract an old num. Maintains a maximum sum of updates. (There is no need for each maintenance update at the time/K, the last/k will be)

Finally, use the biggest sum/k.

　　

In the process of doing this problem, I found that double.min_value is actually more than 0 figures. The integer.min_value used before is clearly the smallest negative number.

Take a look at the definition of Double.min_value: A constant holding the smallest positive nonzero VALUE double of type, 2-1074.

Java Solution:

Runtime beats 51.3%

Completion Date: 10/19/2017

Keywords: Array

Key point: Sliding Window

1 classSolution2 {3      Public DoubleFindmaxaverage (int[] Nums,intk)4     {5         DoubleMav =-Double.max_value;6         DoubleTempmav = 0;7         8          for(inti=0; i<nums.length; i++)9         {TenTempmav + =Nums[i]; One              A             if(i + 1 >=k) -             {    -Mav =Math.max (MAV, TEMPMAV); theTempmav-= nums[i + 1-K]; -             } -               -         } +          -         +         returnMAV/K; A     } at}

Reference: N/A

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Leetcode 643. Maximum Average Subarray I (one of the maximum mean Subarray)