2659. Make Array Empty

Problem Link

Description

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You are given an integer array nums containing distinct numbers, and you can perform the following operations until the array is empty:

• If the first element has the smallest value, remove it
• Otherwise, put the first element at the end of the array.

Return an integer denoting the number of operations it takes to make nums empty.

 

Example 1:

Input: nums = [3,4,-1]
Output: 5

Operation	Array
1	[4, -1, 3]
2	[-1, 3, 4]
3	[3, 4]
4	[4]
5	[]

Example 2:

Input: nums = [1,2,4,3]
Output: 5

Operation	Array
1	[2, 4, 3]
2	[4, 3]
3	[3, 4]
4	[4]
5	[]

Example 3:

Input: nums = [1,2,3]
Output: 3

Operation	Array
1	[2, 3]
2	[3]
3	[]

 

Constraints:

• 1 <= nums.length <= 105
• -109 <= nums[i] <= 109
• All values in nums are distinct.

Solution

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Python3

class Solution:
    def countOperationsToEmptyArray(self, nums: List[int]) -> int:
        N = len(nums)
        A = sorted(range(N), key = lambda i : nums[i])
        res = N
 
        for i in range(N - 1):
            if A[i] > A[i + 1]:
                res += N - i - 1
        
        return res