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

 1 #define _CRT_SECURE_NO_WARNINGS
 2 #include <climits>
 3 #include<iostream>
 4 #include<vector>
 5 #include<queue>
 6 #include<map>
 7 #include<set>
 8 #include<stack>
 9 #include<algorithm>
10 #include<string>
11 #include<cmath>
12 using namespace std;
13 int num[10000];
14 int main()
15 {
16     int N;
17     cin >> N;
18     vector<int> V(N);
19     int n = -1;
20     for (int i = 0; i < N; i++)
21     {
22         cin >> V[i];
23         num[V[i]]++;
24     }
25     for (int i = 0; i < N; i++)
26     {
27         if (num[V[i]] == 1)
28         {
29             n = i;
30             break;
31         }
32     }
33     if (n != -1)
34         cout << V[n];
35     else
36         cout << "None";
37 }

View Code