https://pintia.cn/problem-sets/994805342720868352/problems/994805444361437184
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, 10^4^]. 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 (<=10^5^) 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
代码:
#include <bits/stdc++.h> using namespace std; const int maxn = 1e5 + 10; int a[maxn], num[maxn]; int main() { int n; scanf("%d", &n); for(int i = 1; i <= n; i ++) { scanf("%d", &a[i]); num[a[i]] ++; } int cnt = 0; for(int i = 1; i <= n; i ++) { if(num[a[i]] == 1) { printf("%d\n", a[i]); return 0; } if(num[a[i]] > 1) cnt ++; } if(cnt == n) printf("None\n"); return 0; }
原文地址:https://www.cnblogs.com/zlrrrr/p/9426365.html