PAT1041: Be Unique

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

思路
1084差不多的思路,队列q记录顺序,字典dic记录是否重复出现。遍历q的时候查下字典,输出第一个满足"仅出现一次"的数字即可。
代码
#include<iostream>
#include<map>
#include<iterator>
#include<queue>
using namespace std;
int main()
{
int N;
while(cin >> N)
{
map<int,int> dic;
queue<int> q;
for(int i = ;i < N;i++)
{
int value;
cin >> value;
if(dic.count(value) > )
dic[value] = -;
else
{
q.push(value);
dic.insert(pair<int,int>(value,));
}
} bool check = false;
while(!q.empty())
{
if(dic[q.front()] > )
{
check = true;
cout << q.front();
break;
}
q.pop();
}
if(!check)
cout << "None" << endl;
}
}

 
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