Facebook interview

Facebook is one of the largest and most successful technology companies in the world, and their coding interviews are known to be some of the toughest in the industry. If you're preparing for a Facebook coding interview, there are a few things you can do to increase your chances of success.

First of all, make sure you are comfortable with the basics of computer science, such as algorithms and data structures. Facebook is known to ask questions about these topics, so it's important to have a solid understanding of them. There are many resources available online to help you review these concepts, including books, online courses, and practice problems.

In addition to reviewing the basics, it's also important to practice coding problems. Facebook typically asks candidates to solve coding problems on a whiteboard or in an online coding environment, so it's important to get comfortable with this format. There are many online resources available to help you practice, including websites like LeetCode and HackerRank.

Here's an example coding question that you might encounter in a Facebook interview:

Question: Given a string s and a character c, return an array of integers representing the shortest distance from the character c in the string s.

For example, given the string "facebook" and the character "o", the output should be [5, 4, 3, 2, 1, 0, 0, 1].

Answer: One approach to solving this problem is to loop through the string twice. In the first loop, we start at the beginning of the string and keep track of the position of the last occurrence of the character c. In the second loop, we start at the end of the string and keep track of the position of the next occurrence of the character c. We then calculate the distance between the current position and the closest occurrence of the character c.

def shortest_distance(s, c):
    n = len(s)
    ans = [0] * n
    last = float('-inf')
    
    for i in range(n):
        if s[i] == c:
            last = i
        ans[i] = i - last
    
    last = float('inf')
    for i in range(n-1, -1, -1):
        if s[i] == c:
            last = i
        ans[i] = min(ans[i], last - i)
    
    return ans

shortest_distance("facebook","o")

This code has a time complexity of O(n), where n is the length of the string s.

In conclusion, preparing for a Facebook coding interview requires a solid understanding of computer science basics, as well as practice with coding problems. By reviewing these concepts and practicing problems, you can increase your chances of success in the interview process.