题目
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
记录各个编号的出现次数,输出第一个出现次数为1的数
代码:
#include <iostream>
#include <vector>
using namespace std;
int main()
{
int n;
vector<int> data;
int *flag=new int[100001]; //编号相应数字出现次数标记
int i;
for(i=0;i<100001;i++)
flag[i]=0;
cin>>n;
int temp;
for(i=0;i<n;i++)
{
scanf("%d",&temp);
data.push_back(temp);
flag[temp]++;
}
for(i=0;i<n;i++)
{
if(flag[data[i]]==1)
{
cout<<data[i];
return 0;
}
}
cout<<"None";
return 0;
}