What is the fastest way to sort 1 million integers when integers are from the range [1,100]?

Question

Notes: I\'ve thought about Radix sort, bucket sort, counting sort.

Is there anyway to achieve big O(n)?

Answer 1

Using Radix Sort (In Ruby):

def sort(array)
sorted_array = Array.new(100,[])
array.each do |t|
sorted_array[t-1] = sorted_array[t-1] + [t]
end
sorted_array.flatten!
end