74. The array of numbers that uniquely occur only once

 

No questions asked to do ah Press

class Solution {
public:
    int findNumberAppearingOnce(vector<int>& nums) {
        int n=nums.size()-1;
        unordered_map<int,int > hash;
        for(int i=0;i<=n;i++)
        {
            hash[nums[i]]++;
        }
        for(int i=0;i<=n;i++)
        {
            if(hash[nums[i]] == 1)
            return nums[i];
        }
        
    }
};