PAT.A1041. Be Unique

xiaoxiao2021-03-01  8

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 <cstring> #include <string> #include <algorithm> #include <cmath> #include <map> using namespace std; int main(){ int hash[10010] = { 0 }, a[100010] = { 0 }; int n,i; scanf("%d", &n); for (int i = 1; i <=n; i++) { int b; scanf("%d", &b); a[b] = i; hash[b]++; } int max = 100010,k; for (int i = 1; i <=10000; i++) { if (hash[i] == 1) { if (a[i] < max) { max = a[i]; k = i; } } } if (max == 100010) printf("None"); else printf("%d", k); return 0; }