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