Leetcode--136. Single Number(easy)

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Given a non-empty array of integers, every element appears twice except for one. Find that single one.

Note:

Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

Example 1:

Input: [2,2,1]

Output: 1

Example 2:

Input: [4,1,2,1,2]

Output: 4

class Solution {

    public int singleNumber(int[] nums) {

        int result=;

        for(int i:nums){

            result^=i;

        }

        return result;

    }

}


silly solution

class Solution {

    public int singleNumber(int[] nums) {

        Map<Integer,Integer> mp=new HashMap<Integer,Integer>();

        for(int i:nums){

            mp.put(i,mp.getOrDefault(i,)+);

        }

        for(int i:mp.keySet()){

            if(mp.get(i)<){

                return i;

            }

        }

        return ;

    }

}