class Solution {
public:
vector<int> findNumsAppearOnce(vector<int>& nums) {
unordered_map<int,int>hash;
int x = -1,y =-1;
for(auto x :nums)
hash[x]++;
for(auto& h : hash)
{
if(h.second == 1)
{
if(x == -1)x=h.first;
else y = h.first;
}
}
return {x,y};
}
};