Package g2601_2700.s2654_minimum_number_of_operations_to_make_all_array_elements_equal_to_1

Class Solution

  • public class Solution
extends Object
    2654 - Minimum Number of Operations to Make All Array Elements Equal to 1.

    Medium

    You are given a 0-indexed array nums consisiting of positive integers. You can do the following operation on the array any number of times:

    • Select an index i such that 0 <= i < n - 1 and replace either of nums[i] or nums[i+1] with their gcd value.

    Return the minimum number of operations to make all elements of nums equal to 1. If it is impossible, return -1.

    The gcd of two integers is the greatest common divisor of the two integers.

    Example 1:

    Input: nums = [2,6,3,4]

    Output: 4

    Explanation: We can do the following operations:

    • Choose index i = 2 and replace nums[2] with gcd(3,4) = 1. Now we have nums = [2,6,1,4].
    • Choose index i = 1 and replace nums[1] with gcd(6,1) = 1. Now we have nums = [2,1,1,4].
    • Choose index i = 0 and replace nums[0] with gcd(2,1) = 1. Now we have nums = [1,1,1,4].
    • Choose index i = 2 and replace nums[3] with gcd(1,4) = 1. Now we have nums = [1,1,1,1].

    Example 2:

    Input: nums = [2,10,6,14]

    Output: -1

    Explanation: It can be shown that it is impossible to make all the elements equal to 1.

    Constraints:

    • 2 <= nums.length <= 50
    • 1 <= nums[i] <= 106

    Follow-up:

    The O(n) time complexity solution works, but could you find an O(1) constant time complexity solution?

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • minOperations

        public int minOperations​(int[] nums)