Contains Duplicate
217. Contains Duplicate
μ£Όμ΄μ§ μ μ λ°°μ΄ nums μ κ°μ κ°μ΄ λ λ² μ΄μ λνλλ©΄ true λ₯Ό λ°ννκ³  
λͺ¨λ  μμκ° κ³ μ ν κ°μ΄λΌλ©΄ false λ₯Ό λ°ννλλ‘ μμ±νλΌ.
Example 1:
  Input: nums = [1,2,3,1]
  Output: true
  
Example 2:
  Input: nums = [1,2,3,4]
  Output: false
Example 3:
    Input: nums = [1,1,1,3,3,4,3,2,4,2]
    Output: true
 
Constraints:
  1 <= nums.length <= 10^5
  -10^9 <= nums[i] <= 10^9
Solution
class Solution {
    func containsDuplicate(_ nums: [Int]) -> Bool {
        return Set(nums).count != nums.count
    }
}
μ
λ ₯κ°μΌλ‘ λ€μ΄μ¨ nums λ₯Ό μ€λ³΅μ΄ μλλ‘ Set μΌλ‘ κ°μΈμ£Όμμ λμ μμ κ°μμ 
μλ³Έ μ
λ ₯κ° nums μ μμ κ°μκ° μΌμΉνλμ§λ₯Ό λΉκ΅νμλ€. 
π Reference
LeetCode-217-ContainsDuplicate