题目如下:
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 17Sample Output 1:
31Sample Input 2:
5 888 666 666 888 888Sample Output 2:
None
#include <iostream> #include <map> #include <vector> #include <stdio.h> using namespace std; int main() { map<int,int> numMap; vector<int> nums; int N; cin >> N; int num; for(int i = 0; i < N; i++){ scanf("%d",&num); numMap[num]++; nums.push_back(num); } num = - 1; for(int i = 0; i < nums.size(); i++){ if(numMap[nums[i]] == 1){ num = nums[i]; break; } } if(num == -1) cout << "None" << endl; else cout << num << endl; return 0; }