1041. Be Unique (20)

#include<iostream>#include<algorithm>#include<vector>#include<map> #include<string>#include<set>using namespace std;const int N = 10010;int num[N] = {0}; vector<int> all_num;int main(){int n ;cin>>n;for(int i = 0; i < n; i++){int temp;scanf("%d",&temp);num[temp]++;all_num.push_back(temp);}for(int i = 0; i < n; i++){if(num[all_num[i]] == 1){cout<<all_num[i];return 0;}}cout<<"None";return 0;}