Package g2001_2100.s2090_k_radius_subarray_averages

Class Solution

java.lang.Object
g2001_2100.s2090_k_radius_subarray_averages.Solution
public class Solution extends Object
2090 - K Radius Subarray Averages.

Medium

You are given a 0-indexed array nums of n integers, and an integer k.

The k-radius average for a subarray of nums centered at some index i with the radius k is the average of all elements in nums between the indices i - k and i + k ( inclusive ). If there are less than k elements before or after the index i, then the k-radius average is -1.

Build and return an array avgs of length n where avgs[i] is the k-radius average for the subarray centered at index i.

The average of x elements is the sum of the x elements divided by x, using integer division. The integer division truncates toward zero, which means losing its fractional part.

  • For example, the average of four elements 2, 3, 1, and 5 is (2 + 3 + 1 + 5) / 4 = 11 / 4 = 2.75, which truncates to 2.

Example 1:

Input: nums = [7,4,3,9,1,8,5,2,6], k = 3

Output: [-1,-1,-1,5,4,4,-1,-1,-1]

Explanation:

  • avg[0], avg[1], and avg[2] are -1 because there are less than k elements before each index.

  • The sum of the subarray centered at index 3 with radius 3 is: 7 + 4 + 3 + 9 + 1 + 8 + 5 = 37.

    Using integer division , avg[3] = 37 / 7 = 5.

  • For the subarray centered at index 4, avg[4] = (4 + 3 + 9 + 1 + 8 + 5 + 2) / 7 = 4.

  • For the subarray centered at index 5, avg[5] = (3 + 9 + 1 + 8 + 5 + 2 + 6) / 7 = 4.

  • avg[6], avg[7], and avg[8] are -1 because there are less than k elements after each index.

Example 2:

Input: nums = [100000], k = 0

Output: [100000]

Explanation:

  • The sum of the subarray centered at index 0 with radius 0 is: 100000.

    avg[0] = 100000 / 1 = 100000.

Example 3:

Input: nums = [8], k = 100000

Output: [-1]

Explanation:

  • avg[0] is -1 because there are less than k elements before and after index 0.

Constraints:

  • n == nums.length
  • 1 <= n <= 105
  • 0 <= nums[i], k <= 105

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • getAverages

      public int[] getAverages(int[] nums, int k)