Contains Duplicate LeetCode Solution

Here, We see Contains Duplicate problem Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc., with different approaches.

Contains Duplicate LeetCode Solution

Problem Statement ->

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

• C++ Solution
• Java Solution
• JavaScript Solution
• Python Solution

Contains Duplicate Leetcode Solution C++ ->

class Solution {
public:
    bool containsDuplicate(vector<int>& nums) {
        if (nums.empty()) { return false; }
        unordered_map<int,int> mp;
        for (int i : nums) {
            if (++mp[i] > 1) {
                return true;
            }
        }
        return false;
    }
};
Code language: C++ (cpp)

Contains Duplicate Leetcode Solution Java ->

class Solution {
    public boolean containsDuplicate(int[] nums) {
        if(nums==null || nums.length==0)
            return false;
        HashSet<Integer> hset = new HashSet<Integer>();
        for(int idx: nums){
            if(!hset.add(idx)){
                return true;
            }
        }
        return false;
    }
}
Code language: Java (java)

Contains Duplicate Leetcode Solution JavaScript ->

var containsDuplicate = function(nums) {
    const s = new Set(nums);
return s.size !== nums.length
};
Code language: JavaScript (javascript)

Contains Duplicate Leetcode Python ->

class Solution(object):
    def containsDuplicate(self, nums):
        return len(nums) != len(set(nums))
Code language: Python (python)