PAT A1041 Be Unique

PAT A1041 Be Unique

题目描述：

　　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 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

参考代码：

/****************************************************
PAT A1041 Be Unique
****************************************************/
#include <iostream>
#include <vector>

using namespace std;

int main() {
    int numCnt = 0;

    cin >> numCnt;

    vector<int> Hash(10010, 0);
    vector<int> NumList(numCnt, 0);

    for (int i = 0; i < numCnt; ++i) {
        cin >> NumList[i];
        Hash[NumList[i]]++;
    }
    
    for (int i = 0; i < numCnt; ++i) {
        if (Hash[NumList[i]] == 1) {
            cout << NumList[i];
            return 0;
        }
    }

    cout << "None";

    return 0;
}

注意事项：

　　1：注意理解题目的要求：寻找第一个仅出现一次的数。