PAT甲级真题 1041 Be Unique (20分) C++实现（unordered_map统计元素个数）

最新推荐文章于 2025-09-28 14:35:19 发布

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最新推荐文章于 2025-09-28 14:35:19 发布 · 1.1k 阅读

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该博客介绍了火星上的独特彩票玩法，获胜规则是选择[1, 104]区间内未被他人选择过的数字。博主提供了一个C++解决方案，使用unordered_map来统计每个数字出现的次数，遍历找出第一个出现次数为1的数字作为获胜者。当没有唯一数字时，输出“None”。" 80895470,7586707,Python编程：深入理解函数与字符串操作,"['Python编程', '函数使用', '字符串操作', '数学运算', '数据类型']

题目

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