CF1547B Alphabetical Strings

A string $ s $ of length $ n $ ( $ 1 \le n \le 26 $ ) is called alphabetical if it can be obtained using the following algorithm: - first, write an empty string to $ s $ (i.e. perform the assignment $ s $ := ""); - then perform the next step $ n $ times; - at the $ i $ -th step take $ i $ -th lowercase letter of the Latin alphabet and write it either to the left of the string $ s $ or to the right of the string $ s $ (i.e. perform the assignment $ s $ := $ c+s $ or $ s $ := $ s+c $ , where $ c $ is the $ i $ -th letter of the Latin alphabet). In other words, iterate over the $ n $ first letters of the Latin alphabet starting from 'a' and etc. Each time we prepend a letter to the left of the string $ s $ or append a letter to the right of the string $ s $ . Strings that can be obtained in that way are alphabetical. For example, the following strings are alphabetical: "a", "ba", "ab", "bac" and "ihfcbadeg". The following strings are not alphabetical: "z", "aa", "ca", "acb", "xyz" and "ddcba". From the given string, determine if it is alphabetical.

The first line contains one integer $ t $ ( $ 1 \le t \le 10^4 $ ) — the number of test cases. Then $ t $ test cases follow. Each test case is written on a separate line that contains one string $ s $ . String $ s $ consists of lowercase letters of the Latin alphabet and has a length between $ 1 $ and $ 26 $ , inclusive.

Output $ t $ lines, each of them must contain the answer to the corresponding test case. Output YES if the given string $ s $ is alphabetical and NO otherwise. You can output YES and NO in any case (for example, strings yEs, yes, Yes and YES will be recognized as a positive answer).

The example contains test cases from the main part of the condition.