Contains Duplicate LeetCode Solution | Easy Approach

Minimum Cost to Merge Stones
Share:

Contains Duplicate Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

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 <= 105
  • -109 <= nums[i] <= 109

Contains Duplicate Solutions

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))

Watch Tutorial

Checkout more Solutions here

Leave a Comment

Your email address will not be published. Required fields are marked *

x