Problem of the Day
A new programming or logic puzzle every Mon-Fri

Let's start Thursday off with a tricky problem. Your goal is to great a function that takes in 2 integers and returns the sum of them. The trick is that your program can not use the '+' operator.

Good luck!

Comments:

• Mark - 10 years, 1 month ago

  private int Sum(int a, int b) { var array = new int[] { a, b };

     return array.Sum();
  

  }

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• Jordi - 10 years, 1 month ago

  with nummern (a,b) as                                         
  (select 12, 89 from sysibm/sysdummy1)                         
  select trim(char(a)) concat '+' concat                        
         trim(char(b)) concat '=' concat                        
         trim(char(length(repeat('*',a) concat repeat('*',b)))) 
  from nummern                                                  
  

  ==>

  CONCAT
  12+89=101

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• dpim - 10 years, 1 month ago

  public static int sumInt(int a, int b){
      return a - (-b);
  }
  

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• Anon - 10 years, 1 month ago

    public static int add (int n1, int n2) {
      BigInteger x = BigInteger.valueOf(n1);
      BigInteger y = BigInteger.valueOf(n2);
      BigInteger sum = x.add(y);
      return sum.intValue();
    }
  

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• Anonymous - 10 years, 1 month ago

  Add a negative instead.

  def add(n1,n2):
      return (n1 - (-n2))
  
  print (add(int(input('First number: ')),int(input('Second number: '))))
  

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• Anonymous - 10 years, 1 month ago

  *Subtract a negative, I mean

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• Anonymous - 10 years, 1 month ago

  def add(n1,n2):
      answer = []
      for x in range(n1):
          answer.append(' ')
      for x in range(n2):
          answer.append(' ')
      return(len(answer))
  
  print(add(int(input('First number: ')),int(input('Second number: '))))
  

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• David - 10 years, 1 month ago

  Wow. I really don't even need to take any real effort to circumvent "typical" languages to do this with out explicitly using the build in addition functionality of a given language...

  I will none the less do this in verilog. Because I haven't used it in about a year and a half. Not having a compiler handy on this computer, I really hope my syntax is correct... o.o

  module full_adder(sout, cout, a, b, cin);
    input a, b, cin;
    output sout, cout;
    wire a, b, cin, sout, cout;
    assign sout = (a ^ b) ^ cin;
    assign cout = ((a & b) | (a & cin)) | (b & cin);
  endmodule
  

  module int_adder(Sout, Cout, A, B, Cin);
    input[31:0] A, B;
    input Cin;
    output[31:0] Sout;
    output Cout;
    wire [31:0] A, B, Sout;
    wire Cin, Cout;
    wire[30:0] cout_internal;
    full_adder fa0(   .sout   (Sout[0]),
                      .cout   (cout_internal[0]),
                      .a      (A[0]),
                      .b      (B[0]),
                      .cin    (Cin));
    full_adder fa1(   .sout   (Sout[1]),
                      .cout   (cout_internal[1]),
                      .a      (A[1]),
                      .b      (B[1]),
                      .cin    (cout_internal[0]));
    full_adder fa2(   .sout   (Sout[2]),
                      .cout   (cout_internal[2]),
                      .a      (A[2]),
                      .b      (B[2]),
                      .cin    (cout_internal[1]));
    full_adder fa3(   .sout   (Sout[3]),
                      .cout   (cout_internal[3]),
                      .a      (A[3]),
                      .b      (B[3]),
                      .cin    (cout_internal[2]));
    full_adder fa4(   .sout   (Sout[4]),
                      .cout   (cout_internal[4]),
                      .a      (A[4]),
                      .b      (B[4]),
                      .cin    (cout_internal[3]));
  [...etc...]  
    full_adder fa31(   .sout   (Sout[0]),
                      .cout   (Cout),
                      .a      (A[0]),
                      .b      (B[0]),
                      .cin    (COut));
  
  endmodule //int_adder
  
  

  The output wasn't working conveniently with he online compiler and I lost interest in this specifically. I'm sure there's a bug in here somewhere. And the comment box is complaining at me for posting the full thing in one box -_-
  Here is a code generator in Python:

  for x in range(32):
      if x == 0:
          print """full_adder fa0(   .sout   (Sout[0]),
                      .cout   (cout_internal[0]),
                      .a      (A[0]),
                      .b      (B[0]),
                      .cin    (Cin));"""
      else:
          if x == 31:
              print """  full_adder fa31(   .sout   (Sout[0]),
                      .cout   (Cout),
                      .a      (A[0]),
                      .b      (B[0]),
                      .cin    (COut));"""
          else:
              print """  full_adder fa%i(   .sout   (Sout[%i]),
                      .cout   (cout_internal[%i]),
                      .a      (A[%i]),
                      .b      (B[%i]),
                      .cin    (cout_internal[%i]));""" % (x, x, x, x, x, x-1)
  

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