1041 Be Unique (20 分)
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
Analysis:
The fisrt person who bets on the number which is unique in the array wins;
c++:
#include<stdio.h>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<queue>
#include<set>
#include<math.h>
#include<string.h>
#include<algorithm>
using namespace std;
int main()
{
int n;
int vis[10001];cin>>n;
int a[n];
for(int i=0;i<n;i++){
cin>>a[i];
vis[a[i]]++;
}
int j;
for(j=0;j<n;j++){
if(vis[a[j]]==1){
cout<<a[j]<<endl;
return 0;
}
}
if(j==n)cout<<"None"<<endl;
return 0;
}