cpp-flashcards/org/study_deck_02/dsa/binary-search/0719-find-k-th-smallest-pair-distance.org

#+ANKI_DECK: study_deck_02
* TODO 0719. Find K-th Smallest Pair Distance :hard:
:PROPERTIES:
:NEETCODE: [[file:../../roadmap.org::*0719. Find K-th Smallest Pair Distance][0719. Find K-th Smallest Pair Distance]]
:END:

The *distance of a pair* of integers ~a~ and ~b~ is defined as the absolute difference between ~a~ and ~b~.

Given an integer array ~nums~ and an integer ~k~, return /the/ ~k^{th}~ /smallest *distance among all the pairs*/ ~nums[i]~ /and/ ~nums[j]~ /where/ ~0 <= i < j < nums.length~.

*Example 1:*


#+begin_src
Input: nums = [1,3,1], k = 1
Output: 0
Explanation: Here are all the pairs:
(1,3) -> 2
(1,1) -> 0
(3,1) -> 2
Then the 1st smallest distance pair is (1,1), and its distance is 0.
#+end_src


*Example 2:*


#+begin_src
Input: nums = [1,1,1], k = 2
Output: 0
#+end_src


*Example 3:*


#+begin_src
Input: nums = [1,6,1], k = 3
Output: 5
#+end_src


*Constraints:*

 - ~n == nums.length~

 - ~2 <= n <= 10^{4}~

 - ~0 <= nums[i] <= 10^{6}~

 - ~1 <= k <= n * (n - 1) / 2~

** TODO Approach
Write your approach here.

** TODO Python
#+begin_src python
class Solution:
    def smallestDistancePair(self, nums: List[int], k: int) -> int:
#+end_src

** TODO C++
#+begin_src cpp
class Solution {
public:
    int smallestDistancePair(vector<int>& nums, int k) {
        
    }
};
#+end_src