- Difficulty: Easy
- Tags: LeetCode, Easy, Array, Hash Table, Counting, leetcode-2341, O(n), O(r), Freq Table
Problem
You are given a 0-indexed integer array nums
. In one operation, you may do the following:
- Choose two integers in
nums
that are equal. - Remove both integers from
nums
, forming a pair.
The operation is done on nums
as many times as possible.
Return a 0-indexed integer array answer
of size 2
where answer[0]
is the number of pairs that are formed and answer[1]
is the number of leftover integers in nums
after doing the operation as many times as possible.
Example 1:
Input: nums = [1,3,2,1,3,2,2] Output: [3,1] Explanation: Form a pair with nums[0] and nums[3] and remove them from nums. Now, nums = [3,2,3,2,2]. Form a pair with nums[0] and nums[2] and remove them from nums. Now, nums = [2,2,2]. Form a pair with nums[0] and nums[1] and remove them from nums. Now, nums = [2]. No more pairs can be formed. A total of 3 pairs have been formed, and there is 1 number leftover in nums.
Example 2:
Input: nums = [1,1] Output: [1,0] Explanation: Form a pair with nums[0] and nums[1] and remove them from nums. Now, nums = []. No more pairs can be formed. A total of 1 pair has been formed, and there are 0 numbers leftover in nums.
Example 3:
Input: nums = [0] Output: [0,1] Explanation: No pairs can be formed, and there is 1 number leftover in nums.
Constraints:
1 <= nums.length <= 100
0 <= nums[i] <= 100