问题 C: Be Unique (20)

题目描述

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.

输入

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.

输出

For each test case, print the winning number in a line. If there is no winner, print "None" instead.

样例输入 Copy

7 5 31 5 88 67 88 17
5 888 666 666 888 888

样例输出 Copy

31
None

代码：

#include <bits/stdc++.h>

using namespace std;

const int maxn = 100010;
int hashTable[maxn] = {0};

int main(){
    int n;
    while(scanf("%d", &n)!=EOF){
        vector<int> bets;
        while(n--){
            int temp;
            scanf("%d", &temp);
            bets.push_back(temp);
            hashTable[temp]++;
        }
        int flag = 0;
        for(int i=0; i<bets.size(); i++){
            if(hashTable[bets[i]]==1){
                printf("%d\n", bets[i]);
                flag = 1;
                break;
            }
        }
        if(flag==0) printf("%s\n", "None");
        memset(hashTable, 0, sizeof(hashTable));
    }
    return 0;
}