pat

题目

Being unique is so important to people on Mars that even their lottery is designed in a unique way. The rule of winning is simple: one bets on a number chosen from [$1$,$10^4$]. The first one who bets on a unique number wins. For example, if there are 7 people betting on { 5 31 5 88 67 88 17 }, then the second one who bets on 31 wins.

Input Specification:
Each input file contains one test case. Each case contains a line which begins with a positive integer $N$ (≤$10^5$) and then followed by $N$ bets. The numbers are separated by a space.

Output Specification:
For each test case, print the winning number in a line. If there is no winner, print None instead.

Sample Input1:

7 5 31 5 88 67 88 17

Sample Output1:

31

Sample Input1:

5 888 666 666 888 888

Sample Output1:

None

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#include<map>
#include<vector>
using namespace std;
int (){
    int T,tem;
    scanf("%d",&T);
    map<int,int>m;
    vector<int>v;
    for(int i = 0;i < T;i++){
        scanf("%d",&tem);
        v.push_back(tem);
        m[tem]++;
    }
    for(int i = 0;i < T;i++){
        if(m[v[i]]==1){
            printf("%dn",v[i]);
            return 0;
        }
    }
    printf("Nonen");
    return 0;
}