LeetCode 412: Fizz Buzz

Meta Data

#

Difficulty: easy First Attempt: 2022-08-23

• Submissions: Wrong Answer ×4 → Accepted

Approach

#

Go from 1 to n: test i % 15 == 0 first (or 3 or 5 would claim it), then % 3 and % 5, and otherwise output str(i).

My Attempts

#

The first four submissions were WAs:

• Attempt 1 used // to test multiples (i // 15 == 0 means “less than 15”) and looped only over range(3).
• The next ones hard-coded ["1", "2"] and started at 3; until // was fixed everything became FizzBuzz, and after switching to %, n = 1 still returned two elements. Dropping the hard-coded start passed.

Solution

#

class Solution:
    def fizzBuzz(self, n: int) -> List[str]:
        res = []
        for i in range(1, n + 1):
            if i % 15 == 0:
                res.append("FizzBuzz")
            elif i % 3 == 0:
                res.append("Fizz")
            elif i % 5 == 0:
                res.append("Buzz")
            else:
                res.append(str(i))
        return res

Complexity

#

Time O(n), space O(n) (output).

Mistakes to Avoid

#

• Test multiples with %.
• The range is 1..n; do not hard-code the first elements.
• Convert numbers to strings.

Interview Explanation

#

For 1 to n I check 15 first, then 3 and 5, and otherwise output the number as a string. Time O(n).