Ruby to_s转换为二进制参数错误

Question

I was trying to solve a HackerRank problem which requires binary manipulation. The test cases are extremely huge numbers so I thought better to manipulate them as strings.

t=gets
def winner(pturn)
  if a%2==0 
    puts "Richard\n"
  else 
    puts "Louise\n"
  end
end            

while t != 0
    turn=1
    n=gets
    (n2=n).to_s(2)
    while n!=1
        one="1"
        zero="0"
        if n2.count(1)>1
            zero*=(n2.length - 2)
            one.concat(zero)
            n-=one.to_i(base=2)
        else
            n/=2
        end
     turn+=1
     end 
winner(turn)
t-=1
end

It caused an argument error (wrong number of argument) in line as seen below.

(n2=n).to_s(2)

I think I'm using to_s wrongly. I can't see the mistake and need someone to point it out.

Answer 1

I think you are trying to convert a number in Ruby to a string with it's binary representation. This is possible with (if the number is actually a number in Ruby, eg Fixnum) :

4.to_s 2
# => "100"

But in your case, what you are getting after calling gets is a string, and the to_s method of the String class simply returns itself, and doesn't take any arguments, hence the error.

You can fix it by calling gets.to_i instead of just gets , so the read string of contents will be converted to an integer in Ruby (you should be sure that you will only be reading numbers at there).

And I believe you are trying to assign the binary representation (as a string) of n into the variable n2 , for that you should be doing

n2 = n.to_s(2)

If you just do :

(n2=n).to_s

Because of the parenthesis, first n2 will be assigned the value of n , then to_s will be called on n2 , the string version of n2 will be returned, and nothing else happens. First thing you should be doing is the conversion, then the assignment.

And also you should pass in a string while calling String#count, ie you should call n2.count('2') instead of n2.count(2) .

Answer 2

Argument error is coming because you are trying to pass parameter to to_s method because to_s method never accept any arguments.

So you should change (n2=n).to_s(2) to

(n2=n).to_s