mergesort.coffee
# 配列をマージソート
mergeSort = (ary, isAsc = true)->
tmpAry = ary.concat()
split = (ary)->
if ary.length < 2
return ary
mid = ary.length / 2 | 0
a = split ary.slice 0, mid
b = split ary.slice mid, ary.length
merge ary, a, b
merge = (ary, a, b)->
unless b?
return ary
c = []
aK = bK = cK = 0
while aK < a.length and bK < b.length
if isAsc ^ a[aK] > b[bK]
c[cK] = a[aK]
aK++
else
c[cK] = b[bK]
bK++
cK++
c.concat (if a.length <= aK then b.slice bK else a.slice aK)
split tmpAry