217. Contains Duplicate leetCode

 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

Explanation:

The element 1 occurs at the indices 0 and 3.

Example 2:

Input: nums = [1,2,3,4]

Output: false


Explanation:

All elements are distinct.


import java.util.HashMap;
class Solution {
    public boolean containsDuplicate(int[] nums) {
       
        HashMap<Integer,Integer> map = new HashMap<>();
       
        for(int num:nums)
        {
           map.put(num,map.getOrDefault(num,0)+1);
        }

      for(Map.Entry<Integer,Integer> entry:map.entrySet())
      {
        if(entry.getValue()> 1)
        {
            return true;
        }
      }
      return false;
     
    }
}

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