欢迎来到起遇信息学
起遇信息学正处于上线筹建阶段,以下功能已全部开放免费体验: ✅ 完整题库浏览与代码提交评测(C / C++ / Python / Java 等) ✅ 入门到进阶的系列课程试读、作业与考试 ✅ AI 提示、AI 作业分析等智能助教功能 ✅ 赛事模拟与个人能力报告 ✅ 邮箱注册开放 ⏳ 付费课程订阅与微信/支付宝支付通道 ⏳ 手机号登录,微信扫码登录、微信公众号绑定 使用中如遇任何问题,欢迎通过页面底部 **"联系我们"** 与我们沟通。
CF1173A.Nauuo and Votes
Nauuo and Votes
Nauuo is a girl who loves writing comments.
One day, she posted a comment on Codeforces, wondering whether she would get upvotes or downvotes.
It's known that there were persons who would upvote, persons who would downvote, and there were also another persons who would vote, but you don't know whether they would upvote or downvote. Note that each of the people would vote exactly one time.
There are three different results: if there are more people upvote than downvote, the result will be "+"; if there are more people downvote than upvote, the result will be "-"; otherwise the result will be "0".
Because of the unknown persons, the result may be uncertain (i.e. there are more than one possible results). More formally, the result is uncertain if and only if there exist two different situations of how the persons vote, that the results are different in the two situations.
Tell Nauuo the result or report that the result is uncertain.
Input
The only line contains three integers , , (), corresponding to the number of persons who would upvote, downvote or unknown.
Output
If there is only one possible result, print the result : "+", "-" or "0".
Otherwise, print "?" to report that the result is uncertain.
Note
In the first example, Nauuo would definitely get three upvotes and seven downvotes, so the only possible result is "-".
In the second example, no matter the person unknown downvotes or upvotes, Nauuo would get more upvotes than downvotes. So the only possible result is "+".
In the third example, Nauuo would definitely get one upvote and one downvote, so the only possible result is "0".
In the fourth example, if the only one person upvoted, the result would be "+", otherwise, the result would be "-". There are two possible results, so the result is uncertain.
Samples
3 7 0
-
2 0 1
+
1 1 0
0
0 0 1
?
在线编程 IDE
建议全屏模式获得最佳体验
| 进入全屏编程 | Alt+E |
| 递交评测 | Ctrl+Enter |
| 注释/取消注释 | Ctrl+/ |
| 缩放字体 | Ctrl+滚轮 |