- Difficulty: Easy
- Tags: LeetCode, Easy, Bit Manipulation, Array, Hash Table, Counting, leetcode-2206, O(n)
Problem
You are given an integer array nums
consisting of 2 * n
integers.
You need to divide nums
into n
pairs such that:
- Each element belongs to exactly one pair.
- The elements present in a pair are equal.
Return true
if nums can be divided into n
pairs, otherwise return false
.
Example 1:
Input: nums = [3,2,3,2,2,2] Output: true Explanation: There are 6 elements in nums, so they should be divided into 6 / 2 = 3 pairs. If nums is divided into the pairs (2, 2), (3, 3), and (2, 2), it will satisfy all the conditions.
Example 2:
Input: nums = [1,2,3,4] Output: false Explanation: There is no way to divide nums into 4 / 2 = 2 pairs such that the pairs satisfy every condition.
Constraints:
nums.length == 2 * n
1 <= n <= 500
1 <= nums[i] <= 500