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Thursday Code Puzzler: Square Roots With A Twist

12.06.2012
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Thursday is code puzzler day here at DZone. The idea is simple: solve the coding problem as efficiently as you can, in any language or framework that you find suitable.

Note: Even though there really is nothing stopping you from finding a solution to this on the internet, try to keep honest, and come up with your own answer.  It's all about the participation!

Do you have code puzzlers that you'd like to share with the DZone community?  If so, please submit here. 

Square Roots (With A Twist)

Write a function that calculates the square root of any number, but only uses basic arithmethic such as add, subtract, multiply and divide.  Have Fun!


Catch up on all our previous puzzlers here.

Comments

ebenezer raj replied on Thu, 2012/12/06 - 8:59am

using q:

{{y-((y*y)-x)%2*y}[x] over 1}98 prints 9.8994949
{{y-((y*y)-x)%2*y}[x] over 1}25 prints 5

Daniel Seidler replied on Thu, 2012/12/06 - 10:22am

Kotlin

fun sqrt(x: Double): Double {
    var xn = (x / 2 + 0.5)
    64.times{ xn = (xn + x / xn) / 2 }
    return xn
}

sun east replied on Fri, 2012/12/07 - 12:48am

 Scala:

def sqrt(x: Double): Double = 
    Iterator.iterate(1.0){ r => (r+x/r)/2 }.drop(100).next

scala> sqrt(100)
res0: Double = 10.0

scala> sqrt(1000)
res1: Double = 31.622776601683793

scala> sqrt(3)
res2: Double = 1.7320508075688772


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