643. Maximum Average Subarray I

Posted on Edited on In

643. Maximum Average Subarray I

Description

You are given an integer array nums consisting of n elements, and an integer 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.

Example 1:

1
2
3
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:

1
2
Input: nums = [5], k = 1
Output: 5.00000

Constraints:

  • n == nums.length
  • 1 <= k <= n <= 10^5
  • -10^4 <= nums[i] <= 10^4

Hints/Notes

  • 2024/10/03
  • sliding window
  • No solution from 0x3F

Solution

Language: C++

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
class Solution {
public:
    double findMaxAverage(vector<int>& nums, int k) {
        double res = INT_MIN, sum = 0;
        int right = 0;
        while (right < nums.size()) {
            sum += nums[right];
            if (right >= k - 1) {
                res = max(res, sum / k);
                sum -= nums[right - k + 1];
            }
            right++;
        }
        return res;
    }
};