CF1650A.Deletions of Two Adjacent Letters
普及/提高-
通过率:0%
AC君温馨提醒
该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。
题目描述
The string s is given, the string length is odd number. The string consists of lowercase letters of the Latin alphabet.
As long as the string length is greater than 1 , the following operation can be performed on it: select any two adjacent letters in the string s and delete them from the string. For example, from the string "lemma" in one operation, you can get any of the four strings: "mma", "lma", "lea" or "lem" In particular, in one operation, the length of the string reduces by 2 .
Formally, let the string s have the form s=s1s2…sn ( n>1 ). During one operation, you choose an arbitrary index i ( 1≤i<n ) and replace s=s1s2…si−1si+2…sn .
For the given string s and the letter c , determine whether it is possible to make such a sequence of operations that in the end the equality s=c will be true? In other words, is there such a sequence of operations that the process will end with a string of length 1 , which consists of the letter c ?
输入格式
The first line of input data contains an integer t ( 1≤t≤103 ) — the number of input test cases.
The descriptions of the t cases follow. Each test case is represented by two lines:
- string s , which has an odd length from 1 to 49 inclusive and consists of lowercase letters of the Latin alphabet;
- is a string containing one letter c , where c is a lowercase letter of the Latin alphabet.
输出格式
For each test case in a separate line output:
- YES, if the string s can be converted so that s=c is true;
- NO otherwise.
You can output YES and NO in any case (for example, the strings yEs, yes, Yes and YES will be recognized as a positive response).
输入输出样例
输入#1
5 abcde c abcde b x y aaaaaaaaaaaaaaa a contest t
输出#1
YES NO NO YES YES
说明/提示
In the first test case, s ="abcde". You need to get s ="c". For the first operation, delete the first two letters, we get s ="cde". In the second operation, we delete the last two letters, so we get the expected value of s ="c".
In the third test case, s ="x", it is required to get s ="y". Obviously, this cannot be done.