Maximum Average Subarray I

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You are given an integer array nums consisting of n elements, and an integer k.
您将获得一个由 n 元素组成的整数数组 nums 和一个整数 k .

Find a contiguous subarray whose length is equal to k that has the maximum average value and return this value. Any answer with a calculation error less than 10-5 will be accepted.
找到一个长度等于具有最大平均值 k 的连续子数组，并返回此值。任何计算误差小于 10-5 的答案都将被接受。

Example 1: 示例 1：

Input: nums = [1,12,-5,-6,50,3], k = 4 Output: 12.75000 Explanation: Maximum average is (12 - 5 - 6 + 50) / 4 = 51 / 4 = 12.75

Example 2: 示例 2：

Input: nums = [5], k = 1 Output: 5.00000

Constraints: 约束：

n == nums.length
1 <= k <= n <= 105
-104 <= nums[i] <= 104

package org.leetcode;  
  
public class MaximumAverageSubarrayI {  
    public double findMaxAverage(int[] nums, int k) {  
  
        int sum = 0;  
        for(int i = 0; i < k; i++) {  
            sum = sum + nums[i];  
        }  
  
        int i = k;  
        int j = 0;  
        double result = sum/k;  
        while(i < nums.length) {  
            sum += nums[i];  
            sum -= nums[j];  
            result = Math.max(result, sum/k);  
            i++;  
            j++;  
        }  
        return result;  
    }  
  
    public static void main(String[] args) {  
        MaximumAverageSubarrayI maximumAverageSubarrayI = new MaximumAverageSubarrayI();  
        int[] nums1 = {1,12,-5,-6,50,3};  
        int k1 = 4;  
        double result1 = maximumAverageSubarrayI.findMaxAverage(nums1, k1);  
        double expected1 = 12.75;  
        if(result1 == expected1) {  
            System.out.println("Test 1 passed");  
        } else {  
            System.out.println("Test 1 failed expected: " + expected1 + " actual: " + result1);  
        }  
  
        int[] nums2 = {5};  
        int k2 = 1;  
        double result2 = maximumAverageSubarrayI.findMaxAverage(nums2, k2);  
        double expected2 = 5;  
        if(result2 == expected2) {  
            System.out.println("Test 2 passed");  
        } else {  
            System.out.println("Test 2 failed expected: " + expected2 + " actual: " + result2);  
        }  
    }  
}