1759. Phone List

单点时限: 5.0 sec

内存限制: 256 MB

Given a list of phone numbers, determine if it is consistent in the sense that no number is the prefix of another. Let’s say the phone catalogue listed these numbers:

  • Emergency 911

  • Alice 97 625 999

  • Bob 91 12 54 26

In this case, it’s not possible to call Bob, because the central would direct your call to the emergency line as soon as you had dialled the first three digits of Bob’s phone number. So this list would not be consistent.

输入格式

The first line of input gives a single integer, 1 ≤ t ≤ 40, the number of test cases. Each test case starts with n, the number of phone numbers, on a separate line, 1 ≤ n ≤ 10000. Then follows n lines with one unique phone number on each line. A phone number is a sequence of at most ten digits.

输出格式

For each test case, output “YES” if the list is consistent, or “NO” otherwise.

样例

Input
2
3
911
97625999
91125426
5
113
12340
123440
12345
98346
Output
NO
YES

15 人解决,25 人已尝试。

29 份提交通过,共有 59 份提交。

8.6 EMB 奖励。

创建: 11 年,5 月前.

修改: 1 年,6 月前.

最后提交: 9 月,1 周前.

来源: NCPC 2007

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