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
#include<iostream>
#include<map> using namespace std; int main()
{
int N, temp, index = , min = ;
map<int, int> m; cin >> N; for (int i = ; i<N; ++i)
{
cin >> temp; if (m.find(temp) == m.end())
m.insert(pair<int, int>(temp, index++));
else
m[temp] = ;
} map<int, int>::iterator begin = m.begin(), end = m.end(), i, minIndex; for (i = begin; i != end; ++i)
{
if (i->second> && i->second<min)
{
min = i->second;
minIndex = i;
}
} if (min == )
cout << "None" << endl;
else
cout << minIndex->first << endl;
}