Reading the coding horror, I just came across the FizzBuzz another time.
The original post is here: Coding Horror: Why Can't Programmers.. Program?
For those who do not know: FizzBuzz is a quite popular childrens game. Counting from 1 to 100, and every time a number is divisible by 3 calling "Fizz", every time a number is divisible by 5 calling "Buzz" and every time a number is divisible by 3 and 5, calling "FizzBuzz instead of the number
But this time, I just started to code it down. It was a job of a minute, but there are several things that I do not like.
Here is my code
public void DoFizzBuzz()
{
var combinations = new Tuple<int, string>[]
{
new Tuple<int, string> (3, "Fizz"),
new Tuple<int, string> (5, "Buzz"),
};
for (int i = 1; i <= 100; ++i)
{
bool found = false;
foreach (var comb in combinations)
{
if (i % comb.Item1 == 0)
{
found = true;
Console.Write(comb.Item2);
}
}
if (!found)
{
Console.Write(i);
}
Console.Write(Environment.NewLine);
}
}
So my questions are:
- How to get rid of the bool found?
- Is there a better way of testing than the foreach?
I think what you're trying to accomplish is a generic solution to FizzBuzz, that will work for any number of number-word combinations.
You have a good start - I think I can answer your questions with this example:
public void DoFizzBuzz()
{
var combinations = new List<Tuple<int, string>>
{
new Tuple<int, string> (3, "Fizz"),
new Tuple<int, string> (5, "Buzz"),
};
Func<int, int, bool> isMatch = (i, comb) => i % comb == 0;
for (int i = 1; i <= 100; i++)
{
Console.Write(i);
var matchingCombs = combinations.Where(c => isMatch(i, c.Item1)).ToList();
if (matchingCombs.Any())
{
Console.Write(string.Join("", matchingCombs.Select(c => c.Item2)));
}
else
{
Console.Write(i);
}
Console.Write(Environment.NewLine);
}
}
In practice, you would pass combinations in to the method, but I included it inside just to be concise.
I think your implementation is unnecessarily complex. This one does the job and is easier to understand:
public void DoFizzBuzz()
{
for (int i = 1; i <= 100; i++)
{
bool fizz = i % 3 == 0;
bool buzz = i % 5 == 0;
if (fizz && buzz)
Console.WriteLine ("FizzBuzz");
else if (fizz)
Console.WriteLine ("Fizz");
else if (buzz)
Console.WriteLine ("Buzz");
else
Console.WriteLine (i);
}
}
Take advantage of conditional format specifiers to get a nicely golfed version:
public void DoFizzBuzz()
{
for(int i=1;i<101;i++)Console.WriteLine("{0:#;}{1:;;Fizz}{2:;;Buzz}",i%3*i%5==0?0:i,i%3,i%5);
}
Unrolled for maximum efficiency. This program can outfizzbuzz all others.
public void FizzBuzz()
{
const string FIZZ = "Fizz";
const string BUZZ = "Buzz";
const string FIZZBUZZ = "FizzBuzz";
int i = 0;
while (i < 150)
{
Console.WriteLine(++i);
Console.WriteLine(++i);
Console.WriteLine(FIZZ); ++i;
Console.WriteLine(++i);
Console.WriteLine(BUZZ); ++i;
Console.WriteLine(FIZZ); ++i;
Console.WriteLine(++i);
Console.WriteLine(++i);
Console.WriteLine(FIZZ); ++i;
Console.WriteLine(BUZZ); ++i;
Console.WriteLine(++i);
Console.WriteLine(FIZZ); ++i;
Console.WriteLine(++i);
Console.WriteLine(++i);
Console.WriteLine(FIZZBUZZ); ++i;
}
}
3rd edit:
Here is one way to "get rid of the bool" from your version (that is replace the for loop in your original question with this):
for (int i = 1; i <= 100; i++)
{
var x = combinations.Where(n => i % n.Item1 == 0);
if (x.Count() == 0)
Console.Write(i);
else
Console.Write(string.Join("",x.Select(e => e.Item2)));
Console.Write(Environment.NewLine);
}
Prior answers:
For a pure C# solution check out Keith Thompson's solution.
using System;
class FizzBuzz {
static void Main() {
for (int n = 1; n <= 100; n ++) {
if (n % 15 == 0) {
Console.WriteLine("FizzBuzz");
}
else if (n % 3 == 0) {
Console.WriteLine("Fizz");
}
else if (n % 5 == 0) {
Console.WriteLine("Buzz");
}
else {
Console.WriteLine(n);
}
}
}
}
I worked a bit on FixBuzz using linq. These are the solutions I came up with -- I believe they represent the best way to express the solution to this problem using Linq. (GitHub)
using System;
using System.Linq;
class FizzBuzz {
static void Main() {
var list = Enumerable.Range(1,100)
.Select(n => {
if (n % 15 == 0) {
return "FizzBuzz";
}
if (n % 3 == 0) {
return "Fizz";
}
if (n % 5 == 0) {
return "Buzz";
}
return n.ToString();
});
foreach(string item in list)
Console.WriteLine(item);
}
}
and the crazy one line version:
using System;
using System.Linq;
class FizzBuzz {
static void Main() {
Console.WriteLine(
String.Join(
Environment.NewLine,
Enumerable.Range(1, 100)
.Select(n => n % 15 == 0 ? "FizzBuzz"
: n % 3 == 0 ? "Fizz"
: n % 5 == 0 ? "Buzz"
: n.ToString())
));
}
}
public void DoFizzBuzz()
{
for (int i = 1; i <= 100; i++)
{
if (i % 3 == 0)
Console.Write("Fizz");
if (i % 5 == 0)
Console.Write("Buzz");
if (!(i % 3 == 0 || i % 5 == 0))
Console.Write(i);
Console.Write(Environment.NewLine);
}
}
This gets rid of the bool found, but forces you to do duplicate evaluation. It is slightly different from some of the other answers using i % 15 == 0 for the FizzBuzz qualification. Whether or not this is better is up for debate. However, it is a different way.
Did anyone do this one already?
Enumerable.Range(1, 100).Select(x =>
(x % 15 == 0) ? "FIZZBUZZ"
: (x % 5 == 0) ? "BUZZ"
: (x % 3 == 0) ? "FIZZ"
: x.ToString()
)
.ToList()
.ForEach(console.WriteLine);
Will add my 5 cents to solution by Linq. Everybody is using Select, which is basically Map function. IMHO foldl function suits better to solve this quiz:
Console.WriteLine(
Enumerable
.Range(1, 100)
.Aggregate(new StringBuilder(), (builder, i)
=> i % 15 == 0 ? builder.AppendLine("FizzBuzz")
: i % 3 == 0 ? builder.AppendLine("Fizz")
: i % 5 == 0 ? builder.AppendLine("Buzz")
: builder.AppendLine(i.ToString()))
.ToString());
Linq:
Enumerable.Range(1, 100).ToList().ForEach(i => Console.WriteLine( i % 3 * i % 5 == 0 ? (i % 3 == 0 ? "Fizz" : "") + (i % 5 == 0 ? "Buzz" : "") : i.ToString()));
I think you started with a complicated way. Improving that code would be more complicated. You can use a temp variable to track and display that variable at the end of the FizzBuzz check. Below is code and you can also watch this detail c# FizzBuzz youtube video ( http://www.youtube.com/watch?v=OX5TM3q-JQg ) which explains how the below code is implemented.
for (int j = 1; j <= 100; j++)
{
string Output = "";
if (j % 3 == 0) Output = "Fizz";// Divisible by 3 --> Fizz
if (j % 5 == 0) Output += "Buzz"; // Divisible by 5 --> Buzz
if (Output == "") Output = j.ToString(); // If none then --> number
Console.WriteLine(Output); // Finally print the complete output
}
Not the most efficient, but here's one using C#-6 string interpolation:
void Main()
{
for (int i = 1; i <= 100; i++)
{
Console.WriteLine($"{(i % 15 == 0 ? "FizzBuzz" :
i % 3 == 0 ? "Fizz" :
i % 5 == 0 ? "Buzz" : i.ToString())}");
}
}
Enumerable.Range(1, 100).ToList().ForEach(i=>Console.WriteLine($"{(i%3*i%5==0?0:i):#;}{i%3:;;Fizz}{i%5:;;Buzz}"));
This answer has it all:
- LINQ
- Conditional formatting
- String interpolation
- All on a single line
Victory!
Ok, what the heck, here's the solution I've come to like :)
public void DoFizzBuzz()
{
for (int i = 1; i <= 100; ++i)
{
bool isDivisibleByThree = i % 3 == 0;
bool isDivisibleByFive = i % 5 == 0;
if (isDivisibleByThree || isDivisibleByFive)
{
if (isDivisibleByThree)
cout << "Fizz";
if (isDivisibleByFive)
cout << "Buzz";
}
else
{
cout << i;
}
cout << endl;
}
}
Obviously, this is not the fastest solution, but I like it because it emphasizes readability and makes the "FizzBuzz" case no longer a special case, but something that will happen naturally through the code path.
In the end, what I love most about this question whenever it comes up is that we get to see just how many different solutions ppl can come up with.
You want probably make it configurable, but the question is what should be made configurable - we don't know that. Maybe we should make configurable all the cycle (FizzBuzz has the cycle). Here is very small and fun version with configurable cycle:
string[] fizzBuzzCycle =
"FizzBuzz,{0},{0},Fizz,{0},Buzz,Fizz,{0},{0},Fizz,Buzz,{0},Fizz,{0},{0}"
.Split(',');
for (int i = 1; i <= 100; i++)
Console.WriteLine(fizzBuzzCycle[i%fizzBuzzCycle.Length], i);
So if the strings or whole cycle should be changed it is easy to change. But you just don't know what to make configurable. Maybe condition will change: "for prime numbers print Pizz" and for this modification the solution by @ThomasLevesque is better, because it is easier to change.
The FizzBuzz question is a great interview question. We have started using it in our interview process. It is astounding how many people cannot solve such a simple problem.
Keep in mind, the original blog post was eventually locked due to a flood of people posting more solutions. Hahaha.
Regardless, here is mine in C++! ^_^
#include <iostream>
using namespace std;
int main(int argc, char** argv)
{
for (int i = 1; i <= 100; ++i)
{
bool isMultipleOfThree = (i % 3) == 0;
bool isMultipleOfFive = (i % 5) == 0;
if (isMultipleOfThree) cout << "Fizz";
if (isMultipleOfFive) cout << "Buzz";
if (!isMultipleOfThree && !isMultipleOfFive) cout << i;
cout << '\n';
}
return 0;
}
With the input of Rob H and Jacob Krall here is what I have at the moment. Perhaps I will play around with that in future... just wanted to provide it.
public void DoFizzBuzz()
{
// expect this to come in as parameter
var combinations = new Tuple<int, string>[]
{
new Tuple<int, string> (3, "Fizz"),
new Tuple<int, string> (5, "Buzz"),
};
Func<int, int, bool> isMatch = (i, comb) => i % comb == 0;
// expect the borders 1, 100 to come in as parameters
for (int i = 1; i <= 100; ++i)
{
var matchingCombs = combinations.Where(c => isMatch(i, c.Item1)).DefaultIfEmpty(new Tuple<int, string>(i, i.ToString())).Aggregate((v, w) => new Tuple<int, string>(v.Item1, v.Item2 + w.Item2)).Item2;
Console.WriteLine(matchingCombs);
}
}
I would suggest this compact code as an addition to the previous simple and nice versions.
for (int i = 1; i <= 100; i++) // i++ but not ++i as in your example, be careful here
{
bool fizz = i % 3 == 0;
bool buzz = i % 5 == 0;
string output = fizz && buzz ? "FizzBuzz" :
fizz ? "Fizz" :
buzz ? "Buzz" :
i.ToString();
Console.WriteLn(output);
}
I am a beginner, here is my attempt:
public void DoFizzBuzz()
{
for (int i = 1; i < 101; i++)
{
if ((i % 3 == 0) && (i % 5 == 0))
{
Console.WriteLine("{0} FizzBuzz", i);
}
else if (i % 3 == 0)
{
Console.WriteLine("{0} Fizz", i);
}
else if (i % 5 == 0)
{
Console.WriteLine("{0} Buzz", i);
}
else
{
Console.WriteLine(i);
}
}
Console.ReadLine();
}
Is there anything wrong with my approach? Mine seems a lot simpler than everyone's else approach so it must be wrong.
In my opinion, the FizzBuzz problem is always presented as a challenge to the interviwee to make the word FizzBuzz appear without explicitly printing it. Here is my solution in C#.
internal void PrintFizzBuzzAlternative(int num)
{
if (num % 5 == 0)
Console.Write("Fizz");
if (num % 3 == 0)
Console.Write("Buzz");
if (num % 5 != 0 && num % 3 != 0)
Console.Write(num);
Console.WriteLine();
}
A functional approach...
Console.WriteLine(Enumerable
.Range(1,100)
.Aggregate("",
(a,i) => a + "\n" + (i%15==0 ? "fizzbuzz" :
(i%5==0 ? "buzz" :
(i%3==0 ? "fizz" : i.ToString())))));
I tried to solve this problem without looking at the answers. It took me 3 hours to succeed. (I'm just a hobby programmer by the way so don't bash me hard please :)) This is my c# version solution:
static void Main(string[] args)
{
for (int i = 1; i <= 100; i++)
{
if( ((i % 3) != 0) && ((i % 5) != 0))
{
WriteLine($"{i}");
}
else
{
if ((i % 15) == 0)
{
WriteLine("FizzBuzz");
}
else if ((i % 3) == 0)
{
WriteLine("Fizz");
}
else if ((i % 5) == 0)
{
WriteLine("Buzz");
}
}
}
}
Relatively simple solution using a for loop.
No Linq or anything - just basic shorthand if statements
for(int x=1;x<101;x++)
Console.WriteLine(x%3==0?"Fizz"+(x%5==0?"Buzz":""):x%5==0?"Buzz":x+"");
The Linq solution which is a lot like csells (sans string interpolation) and fits on one line would be:
Enumerable.Range(1,100).ToList().ForEach(x=>Console.WriteLine(x%3==0?"Fizz"+(x%5==0?"Buzz":""):x%5==0?"Buzz":x+""));
The null-coalescing operator is really useful:
string output = null;
for (int i = 1; i <= 100; i++)
{
if (i % 3 == 0) output += "fizz";
if (i % 5 == 0) output += "buzz";
Console.WriteLine(output ?? i.ToString());
output = null;
}
Console.ReadKey();
I'll add mine even though there's 20 other solutions already written: It goes like this....
var x = 1;
while (x <= 100)
{
if (x % 3 == 0 && x % 5 == 0)
{Console.Writeline("FizzBuzz");}
else if (x % 3 == 0)
{Console.Writeline("fizz");}
else if (x % 5 == 0)
{Console.Writeline("Buzz");}
else
{Console.Writeline(x);}
x++
}
First solution I came up with. Simple, to the point and gets the job done. No need for bool.
I recommend using the ++i instead of the i++ in a for loop because i++ requires a copy to be made ;)
public void DoFizzBuzz()
{
for (int i = 1; i < 101; ++i)
{
if (i % 15 == 0)
Console.WriteLine ("FizzBuzz");
else if (i % 3 == 0)
Console.WriteLine ("Fizz");
else if (i % 5 == 0)
Console.WriteLine ("Buzz");
else
Console.WriteLine (i);
}
}
The original questions were: 1.How to get rid of the bool found? 2.Is there a better way of testing than the foreach?
This gets rid of the bool and the foreach, and I think it's still readable.
public static void DoFizzBuzz()
{
var combinations = new Tuple<int, string>[]
{
new Tuple<int, string> (3, "Fizz"),
new Tuple<int, string> (5, "Buzz"),
};
for (int i = 1; i <= 100; i++)
{
var fb = combinations.Where(t => {
if (i % t.Item1 == 0)
{
Console.Write(t.Item2);
return true;
}
return false;
}).ToList();
if (!fb.Any())
{
Console.Write(i);
}
Console.Write(Environment.NewLine);
}
}
Who'd a thunk we'd be getting so excited about a simple kids game? :)
You can use either use this and only take the amount you want
static void Main(string[] args)
{
GetFizzBuzz().Take(100).ToList().ForEach(Console.WriteLine);
}
private static IEnumerable<string> GetFizzBuzz()
{
for (var i = 0; i < int.MaxValue; i++)
{
if (i % 3 == 0 && i % 5 == 0) yield return "FizzBuzz";
if (i % 3 == 0) yield return "Fizz";
yield return i % 5 == 0 ? "Buzz" : i.ToString(CultureInfo.InvariantCulture);
}
}
Or simply use this :
Enumerable.Range(1, 100).Select(s => {
if (s % 3 == 0 && s % 5 == 0) return "FizzBuzz";
if (s % 3 == 0) return "Fizz";
return s%5 == 0 ? "Buzz" : s.ToString(CultureInfo.InvariantCulture);
}).ToList().ForEach(Console.WriteLine);
Obviously this is a bit outside the spirit of the FizzBuzz challenge. But in my benchmark this was the fastest I could make it while single threaded and still terminating at 100. It is semi-unrolled and uses a StringBuilder. It is approximately three times faster than the standard approach.
const string FIZZ = " Fizz\n";
const string BUZZ = " Buzz\n";
const string FIZZBUZZ = " FizzBuzz\n";
...
var sb = new StringBuilder();
int i = 0;
while(true)
{
sb.Append(i+3);
sb.Append(FIZZ);
sb.Append(i+5);
sb.Append(BUZZ);
sb.Append(i+6);
sb.Append(FIZZ);
sb.Append(i+9);
sb.Append(FIZZ);
sb.Append(i+10);
sb.Append(BUZZ);
if(i+12 > 100)
break;
sb.Append(i+12);
sb.Append(FIZZ);
i+=15;
sb.Append(i);
sb.Append(FIZZBUZZ);
}
Console.Write(sb.ToString());
With no if conditions, just one ternary operator.
string[] s = new string[6]{"Fizz", "Buzz", "", "", "", ""};
for (int i = 1; i <= 100; i++)
{
string output = s[(i%3)*2] + s[(i%5)+1];
Console.WriteLine(string.IsNullOrEmpty(output)? "" + i : output);
}
Without using any If's, C# code.
//False = 0, True = 1.
private void DivisibilityByFiveThreeTest(int num)
{
string[,] values = new string [2,2]{
{"None","Fizz"},
{"Buzz","FizzBuzz"}
};
for(int i=1;i< num;i++)
Console.WriteLine(values[Convert.ToInt32(i % 5 == 0), Convert.ToInt32(i%3==0)]);
}
来源：https://stackoverflow.com/questions/11764539/writing-fizzbuzz