Package g2601_2700.s2654_minimum_number_of_operations_to_make_all_array_elements_equal_to_1

Class Solution

java.lang.Object
g2601_2700.s2654_minimum_number_of_operations_to_make_all_array_elements_equal_to_1.Solution
public class Solution extends java.lang.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 Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    minOperations(int[] nums)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • minOperations

      public int minOperations(int[] nums)