A1041. Be Unique

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<cstdio>
#include<iostream>
using namespace std;
int hashTB[10001] = {0,0}, record[100000];
int main(){
    int N, find = -1;
    scanf("%d", &N);
    for(int i = 0; i < N; i++){
        scanf("%d", &record[i]);
        hashTB[record[i]]++;
    }
    for(int i = 0; i < N; i++){
        if(hashTB[record[i]] == 1){
            find = i;
            break;
        }
    }
    if(find == -1)
        printf("None");
    else printf("%d", record[find]);
    cin >> N;
    return 0;
}

总结：

1、本题题意：按照输入的顺序，找出第一个只出现一次的数字并输出。