# PAT (Advanced Level)-1041. Be Unique (20)

PAT (Advanced Level)-1041. Be Unique (20)

## 1041. Be Unique (20)

100 ms

65536 kB

CHEN, Yue

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, 104]. 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 (<=105) 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``

## 完整代码

``````#include<iostream>
#include<vector>
#include<map>

int main()
{
int N;
std::cin >> N;
std::vector<int> record_num;
std::map<int, int> record_unique;
for (int i = 0; i < N; i++)
{
int num;
std::cin >> num;
record_unique[num]++;
record_num.push_back(num);
}

bool flag_num = false;
int result;
for (int i = 0; i < record_num.size(); i++)
{
if (record_unique[record_num[i]] == 1)
{
flag_num = true;
result = record_num[i];
break;
}
}

if (flag_num == false)
{
std::cout << "None" << std::endl;
}
else
{
std::cout << result << std::endl;
}
return 0;
}``````