3267 - Count Almost Equal Pairs II.

Hard

Attention: In this version, the number of operations that can be performed, has been increased to twice.

You are given an array nums consisting of positive integers.

We call two integers x and y almost equal if both integers can become equal after performing the following operation at most <ins>twice</ins>:

• Choose either x or y and swap any two digits within the chosen number.

Return the number of indices i and j in nums where i < j such that nums[i] and nums[j] are almost equal.

Note that it is allowed for an integer to have leading zeros after performing an operation.

Example 1:

Input: nums = 1023,2310,2130,213

Output: 4

Explanation:

The almost equal pairs of elements are:

• 1023 and 2310. By swapping the digits 1 and 2, and then the digits 0 and 3 in 1023, you get 2310.

• 1023 and 213. By swapping the digits 1 and 0, and then the digits 1 and 2 in 1023, you get 0213, which is 213.

• 2310 and 213. By swapping the digits 2 and 0, and then the digits 3 and 2 in 2310, you get 0213, which is 213.

• 2310 and 2130. By swapping the digits 3 and 1 in 2310, you get 2130.

Example 2:

Input: nums = 1,10,100

Output: 3

Explanation:

The almost equal pairs of elements are:

• 1 and 10. By swapping the digits 1 and 0 in 10, you get 01 which is 1.

• 1 and 100. By swapping the second 0 with the digit 1 in 100, you get 001, which is 1.

• 10 and 100. By swapping the first 0 with the digit 1 in 100, you get 010, which is 10.

Constraints:

• 2 <= nums.length <= 5000

• <code>1 <= numsi< 10⁷</code>