选择排序

def minindex array_,index_
  index=nil
  beginindex = 0
  minvalue = array_[0]
  if index_ > 0
    beginindex=index_+1
    minvalue = array_[index_]
  end
    for j in beginindex...array_.size
      if array_[j] < minvalue
        minvalue =array_[j]
        index=j
      end
    end
  return index
end

for j in 0...array.size-1
  oldmin=minindex array,j
  if oldmin!=nil
  key=array[j]
  array[j]=array[oldmin]
  array[oldmin]=key
  end
end