1041 Be Unique (20分)(水)

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]. 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 (≤) 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 Input 1:

7 5 31 5 88 67 88 17

Sample Output 1:

31

Sample Input 2:

5 888 666 666 888 888

Sample Output 2:

None

#define _CRT_SECURE_NO_WARNINGS
#include <climits>
#include<iostream>
#include<vector>
#include<queue>
#include<map>
#include<set>
#include<stack>
#include<algorithm>
#include<string>
#include<cmath>
using namespace std;
int num[10000];
int main()
{
    int N;
    cin >> N;
    vector<int> V(N);
    int n = -1;
    for (int i = 0; i < N; i++)
    {
        cin >> V[i];
        num[V[i]]++;
    }
    for (int i = 0; i < N; i++)
    {
        if (num[V[i]] == 1)
        {
            n = i;
            break;
        }
    }
    if (n != -1)
        cout << V[n];
    else
        cout << "None";
}