Created
December 12, 2012 22:31
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Merge sort in Scala using pattern matching
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| def mergeSort[T <: Ordered[T]](xs:List[T]): List[T] = { | |
| def merge(xs:List[T], ys:List[T]): List[T] = { | |
| (xs,ys) match { | |
| case (Nil,_) => ys | |
| case (_,Nil) => xs | |
| case (x::xs1, y::ys1) => { | |
| if (x < y) { | |
| x::merge(xs1,ys) | |
| } else { | |
| y::merge(xs,ys1) | |
| } | |
| } | |
| } | |
| } | |
| if (xs.isEmpty) { | |
| xs | |
| } else { | |
| val n = xs.length / 2 | |
| val (ys,zs) = xs.splitAt(n) | |
| merge(mergeSort(ys), mergeSort(zs)) | |
| } | |
| } | |
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