class Solution {
public:
int findNumberAppearingOnce(vector[HTML_REMOVED]& nums) {
//vector[HTML_REMOVED] a;
unordered_map[HTML_REMOVED] res;
for(int i = 0;i < nums.size();i ) res[nums[i]];
for(unordered_map[HTML_REMOVED]::iterator iter=res.begin();iter!=res.end();iter++)
{
// 如果value=1，输出key值并压入a容器中
if(iter->second == 1) return iter->first;
}
//return a;
}
};