PAT_1041. Be Unique

////  main.cpp//  PAT_1041. Be Unique////  Created by wjq on 17/5/8.//  Copyright © 2017年 wjq. All rights reserved.//#include <iostream>#include <string.h>using namespace std;int A[100005],N,temp,i,B[100005],j=0;int main(int argc, const char * argv[]){    memset(A,0,sizeof(A));    cin>>N;    for(i=0;i<N;i++)    {        cin>>temp;        A[temp]++;        if(A[temp]==1)            B[j++]=temp;    }    for(i=0;i<100005;i++)    {        if(A[B[i]]==1)            break;    }    if(i!=100005)        cout<<B[i];    else        cout<<"None";    return 0;}

简单题