2206. Divide Array Into Equal Pairs

#### QUESTION:

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
``````

#### EXPLANATION:

easy的题目, 也就不多说了, 一个for循环.

#### SOLUTION:

``````class Solution {
func divideArray(_ nums: [Int]) -> Bool {
var arr:[Int] = nums.sorted()
for index in stride(from: 0, to: arr.count, by: 2) {
if arr[index] != arr[index+1] {
return false
}
}
return true
}
}
``````