Leetcode

Contains Duplicate

May 26, 2022 by aAshish

  • Time:O(n)
  • Space:O(n)

C++

 
class Solution {
 public:
  bool containsDuplicate(vector<int>& nums) {
    unordered_set<int> seen;

    for (const int num : nums)
      if (!seen.insert(num).second)
        return true;

    return false;
  }
};

JAVA

 
class Solution {
  public boolean containsDuplicate(int[] nums) {
    Set<Integer> seen = new HashSet<>();

    for (final int num : nums)
      if (!seen.add(num))
        return true;

    return false;
  }
}

Python

 
class Solution:
  def containsDuplicate(self, nums: List[int]) -> bool:
    return len(nums) != len(set(nums))