PAT甲级1041. Be Unique (20)

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 <vector>using namespace std;const int MAX=100000+10;int cnt[MAX]={0};int main(){    int N;    scanf("%d",&N);    vector<int> V(N);    for(int i=0;i<N;i++){        scanf("%d",&V[i]);        cnt[V[i]]++;    }    int flag=0;    for(int i=0;i<N;i++){        if(cnt[V[i]]==1) {            printf("%d",V[i]);            flag=1;            break;        }    }    if(!flag) printf("None");    return 0;}