PAT-A-1041. Be Unique (20)

1041. Be Unique (20)

时间限制

100 ms

内存限制

65536 kB

代码长度限制

16000 B

判题程序

Standard

作者

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

#include<iostream>#include<cstdio>using namespace std;int a[100010] = { 0 };int b[10001] = { 0 };int main(){  int n;  int m = -1;  cin >> n;  for (int i = 0; i < n; i++)  {    cin >> a[i];    b[a[i]]++;  }  for (int i = 0; i < n; i++)  {    if (b[a[i]] == 1)    {      m = a[i];      break;    }  }    if (m == -1)    cout << "None" << endl;  else    cout << m;  system("pause");  return 0;}