String Interview Questions

No. 07 - Reverse words in a sentence
Reverse the order of words in a sentence, but keep words themselves unchanged. Words in a sentence are divided by blanks. For instance, the reversed output should be “student. a am I” when the input is “I am a student”.

No. 13 - First Character Appearing Only Once
Implement a function to find the first character in a string which only appears once.

For example: It returns ‘b’ when the input is “abaccdeff”.

No. 19 - Left Rotation of String
Left rotation of a string is to move some leading characters to its tail. Please implement a function to rotate a string. For example, if the input string is “abcdefg” and a number 2, the rotated result is “cdefgab”.

No. 43 - Minimal Number of Palindromes on a String
A string can be partitioned into some substrings, such that each substring is a palindrome. For example, there are a few strategies to split the string “abbab” into palindrome substrings, such as: “abba”|”b”, “a”|”b”|”bab” and “a”|”bb”|”a”|”b”.

No. 55 - Translating Numbers to Strings
Given a number, please translate it to a string, following the rules: 1 is translated to 'a', 2 to 'b', …, 12 to 'l', …, 26 to 'z'. For example, the number 12258 can be translated to "abbeh", "aveh", "abyh", "lbeh" and "lyh", so there are 5 different ways to translate 12258. How to write a function/method to count the different ways to translate a number?