Recently, I've been helping a few students prepare TikTok The VO interview, really feel the company on the technical details and communication skills of the double requirements. The whole process is very fast-paced, and the topics are very "close to the real world". From algorithms, system design to behavioral interviews, each round should not be taken lightly! This interview will organize the whole process of TikTok VO that we took our students through, including the specific content of each round, the questions we encountered, the interviewer's concerns, and some preparation tips ~ I hope it can help you, who are rushing to TikTok or other big companies, to take less detours and get the offer steadily!
TikTok VO Interview Questions I:
Given a string s, return true if it is a palindrome, false otherwise. input: s = "aba" output: true
This is a relatively simple problem, basically checking to see if a string reads the same from front to back as it does from back to front. A palindromic string is defined in such a way that the forward and reverse order are the same.
Idea 1. Use the REVERSE method:
The easiest way to do this is to reverse the string and then compare whether the reversed string is the same as the original string.
time complexity: O(n), where n is the length of the string, since the reverse operation requires traversing the entire string.
(math.) space complexity: O(n), requires extra space to store the reversed string.
Idea 2. Use the double pointer method:
The double pointer method starts at the beginning and end of the string at the same time, moves to the middle, and compares the characters pointed to by the two pointers at each step to see if they are the same.
def is_palindrome(s).
left, right = 0, len(s) - 1
while left < right: if s[left] !
if s[left] ! = s[right]: if s[left] !
return False
left, right = left + 1, right - 1
return True
time complexity: O(n), may traverse half the string.
(math.) space complexity: O(1), requiring only constant-level extra space.
Comparison:
- performances: The double-pointer method can end early on a non-return, and the inverse method must traverse the complete string.
- spatial efficiency: Dual pointers save memory by eliminating the need to create a copy.
- readable: The inversion approach is more concise and easier to understand and maintain for common scenarios.
TikTok VO Interview Questions II:
You have a string s. You can convert it to a palindrome by adding characters before it. Return the shortest palindrome you can find by this conversion. Input: s = "aaacecaaa" Output: "aaacecaaa"
This problem is more complex than the first one and requires constructing the echo string by adding characters.
The solution is to compare s with its reverse string s' to find the longest prefix-suffix match, and then add the unmatched part of s' to the front of s to form the shortest palindrome string.
Specific Steps:
- Creates the reverse string s' of s.
- Compare character by character from the beginning of s to the end of s' to find the longest matching prefix.
- Adds the unmatched part of s' to the front of s.
The implementation needs to be aware of boundary conditions, such as the case of an empty string or a string that is already a palindrome.
TikTok VO interview process:
In the interview, the first problem was solved and ideas were discussed, the interviewer was happy with the pseudo-code and boundary condition discussion. The first problem code passed all tests quickly.
The second question started without fully understanding the question and quickly adjusted after the interviewer reminded him to pass all the test cases.
The interviewer gave me positive feedback on my code style, algorithm optimization suggestions and performance issues with large data sets.
Overall, this interview not only tested programming skills, but also practiced problem solving and communication and collaboration skills. It is possible to Contact Us Get more interview experience and coaching services.
