PAT A1041. Be Unique (20)

1. Be Unique (20)

時間限制
100 ms
內存限制
65536 kB
代碼長度限制
16000 B
判題程序
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

#include<cstdio>
const int maxn=100010;
int a[maxn];
int n;
int count[10009]={0};

int main(){
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        scanf("%d",a+i);
        count[a[i]]++;
    }
    for(int i=0;i<n;i++){
        if(count[a[i]]==1){
            printf("%d",a[i]);
            return 0;
        }
    }
    printf("None");
    return 0;
}