Problem of The Day: Fizz Buzz

3 min read 791 words

Problem Statement

leetcode problem link

Solution [Accepted]

public class Solution {
    public IList<string> FizzBuzz(int n) {
        IList<string> result = new List<string>();
        for (int i = 1; i < n + 1; i++) {
            if (i % 3 == 0 && i % 5 == 0) {
            result.Add("FizzBuzz");
            }
            else if (i % 3 == 0) {
                result.Add("Fizz");
            }
            else if (i % 5 == 0) {
                result.Add("Buzz");
            } else {
                result.Add(i.ToString());
            }
        }
        return result;
    }
}

Time: O(n) Space: O(1)

Editorial

Approach 1: Naive Approach

class Solution:
    def fizzBuzz(self, n: int) -> List[str]:
        # ans list
        ans = []

        for num in range(1,n+1):

            divisible_by_3 = (num % 3 == 0)
            divisible_by_5 = (num % 5 == 0)

            if divisible_by_3 and divisible_by_5:
                # Divides by both 3 and 5, add FizzBuzz
                ans.append("FizzBuzz")
            elif divisible_by_3:
                # Divides by 3, add Fizz
                ans.append("Fizz")
            elif divisible_by_5:
                # Divides by 5, add Buzz
                ans.append("Buzz")
            else:
                # Not divisible by 3 or 5, add the number
                ans.append(str(num))

        return ans

Approach 2: String Concatenation

class Solution:
    def fizzBuzz(self, n: int) -> List[str]:
        # ans list
        ans = []

        for num in range(1,n+1):

            divisible_by_3 = (num % 3 == 0)
            divisible_by_5 = (num % 5 == 0)

            num_ans_str = ""

            if divisible_by_3:
                # Divides by 3
                num_ans_str += "Fizz"
            if divisible_by_5:
                # Divides by 5
                num_ans_str += "Buzz"
            if not num_ans_str:
                # Not divisible by 3 or 5
                num_ans_str = str(num)

            # Append the current answer str to the ans list
            ans.append(num_ans_str)

        return ans

Approach 3: Hash it!

class Solution:
    def fizzBuzz(self, n: int) -> List[str]:
        # ans list
        ans = []

        # Dictionary to store all fizzbuzz mappings
        fizz_buzz_dict = {3 : "Fizz", 5 : "Buzz"}

        # List of divisors which we will iterate over.
        divisors = [3, 5]

        for num in range(1, n + 1):

            num_ans_str = []

            for key in divisors:
                # If the num is divisible by key,
                # then add the corresponding string mapping to current num_ans_str
                if num % key == 0:
                    num_ans_str.append(fizz_buzz_dict[key])

            if not num_ans_str:
                num_ans_str.append(str(num))

            # Append the current answer str to the ans list
            ans.append(''.join(num_ans_str))

        return ans