2966. Divide Array Into Arrays With Max Difference

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題目敘述

You are given an integer array nums of size n and a positive integer k.

Divide the array into one or more arrays of size 3 satisfying the following conditions:

• Each element of nums should be in exactly one array.
• The difference between any two elements in one array is less than or equal to k.

Return a 2D array containing all the arrays. If it is impossible to satisfy the conditions, return an empty array. And if there are multiple answers, return any of them.

Example 1

Input: nums = [1,3,4,8,7,9,3,5,1], k = 2 Output: [[1,1,3],[3,4,5],[7,8,9]] Explanation: We can divide the array into the following arrays: [1,1,3], [3,4,5] and [7,8,9]. The difference between any two elements in each array is less than or equal to 2. Note that the order of elements is not important.

Example 2

Input: nums = [1,3,3,2,7,3], k = 3 Output: [] Explanation: It is not possible to divide the array satisfying all the conditions.

解題思路

Solution

import java.util.Arrays;

class Solution {
    public int[][] divideArray(int[] nums, int k) {
        int size = nums.length;
        if(size % 3 != 0){
            return new int[0][0];
        }

        Arrays.sort(nums);

        int[][] ans = new int[(size / 3)][3];

        for(int i = 0, j = 0; j < (size / 3); i += 3, j++){
            if(i + 2 < size && nums[i + 2] - nums[i] <= k){
                ans[j][0] = nums[i];
                ans[j][1] = nums[i + 1];
                ans[j][2] = nums[i + 2];
            }else{
                return new int[0][0];
            }
        }

        return ans;
    }
}