Problem
A sequence of numbers is called an arithmetic progression if the difference between any two consecutive elements is the same.
Given an array of numbers arr, return true **if the array can be rearranged to form an **arithmetic progression. Otherwise, return false.
Example 1:
Input: arr = [3,5,1]
Output: true
Explanation: We can reorder the elements as [1,3,5] or [5,3,1] with differences 2 and -2 respectively, between each consecutive elements.
Example 2:
Input: arr = [1,2,4]
Output: false
Explanation: There is no way to reorder the elements to obtain an arithmetic progression.
Constraints:
2 <= arr.length <= 1000-106 <= arr[i] <= 106
Solution
/**
* @param {number[]} arr
* @return {boolean}
*/
var canMakeArithmeticProgression = function(arr) {
if (arr.length <= 2) return true;
arr.sort((a, b) => a - b);
const differ = arr[1] - arr[0];
return arr.every((item, i) => i === 0 || item - arr[i - 1] === differ);
};
Explain:
nope.
Complexity:
- Time complexity : O(nlogn).
- Space complexity : O(1).