Minimum Replacements to Sort the Array

arraymathgreedy

Problem Statement

You are given a 0-indexed integer array nums . In one operation you can replace any element of the array with any two elements that sum to it.

For example, consider nums = [5,6,7] . In one operation, we can replace nums[1] with 2 and 4 and convert nums to [5,2,4,7] .

Return the minimum number of operations to make an array that is sorted in non-decreasing order .

Examples

Example 1

Input: nums = [3,9,3]
Output: 2
Here are the steps to sort the array in non-decreasing order:
- From [3,9,3], replace the 9 with 3 and 6 so the array becomes [3,3,6,3]
- From [3,3,6,3], replace the 6 with 3 and 3 so the array becomes [3,3,3,3,3]
There are 2 steps to sort the array in non-decreasing order. Therefore, we return 2.

Example 2

Input: nums = [1,2,3,4,5]
Output: 0
The array is already in non-decreasing order. Therefore, we return 0.

Constraints

1 <= nums.length <= 10 ^5

1 <= nums[i] <= 10 ^9

😤

Hard

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicMath