A Pythagorean triplet is a set of three natural numbers, a b c, for which,

a² + b² = c²

For example, 3² + 4² = 9 + 16 = 25 = 5².

There exists exactly one Pythagorean triplet for which a + b + c = 1000.
Find the product abc.

p9()->p9(334).
p9(C)->p9(1,C).
p9(C,C)->p9(1,C+1);
p9(B,C)->
	A=1000-C-B,
	if
		C*C == A*A + B*B->
			io:format("~w~n",[A*B*C]);
		true->
			p9(B+1,C)
	end.

def p9
  (2..500).each do |a|
    (1...a).each do |b|
      if(a**2+b**2==(1000-a-b)**2)
        puts a*b*(1000-a-b)
        return
      end
    end
  end
end

+-//pow
def pow(a: BigInt, b: Int)={
  def loop(res: BigInt, mult: BigInt, shift:Int): BigInt={
    if(shift==0) res
    else{
      if(shift%2==0) loop(res, mult*mult, shift >> 1)
      else loop(res*mult, mult*mult, shift >>1)
    }
  }
  loop(1,a,b)
}

def p9{
  for(c<-334 to 1000; b<-2 to (c-1)){
    if(c*c==b*b+pow(1000-c-b,2).intValue)
    {
      println(c*b*(1000-c-b))
      return
    }
  }
}