big o - Can an algorithm have a runtime of O(2n)? -


this question has answer here:

if algorithm iterates on list of numbers 2 times before returning answer runtime o(2n) or o(n)? runtime of algorithm lack coefficient?

it may still slower implementation doesn't iterate twice, still o(n), time complexity scales based on size of n.


Comments

Post a Comment

Popular posts from this blog

Python Kivy ListView: How to delete selected ListItemButton? -

Image
i'm trying learn kivy building simple todo-list app suggested dusty phillips, author of book "creating apps in kivy". this code far: from kivy.app import app kivy.uix.boxlayout import boxlayout kivy.properties import objectproperty kivy.uix.listview import listitembutton class taskbutton(listitembutton): pass class todoroot(boxlayout): task_input = objectproperty() task_list = objectproperty() def add_task(self): self.task_list.adapter.data.extend([self.task_input.text]) self.task_list._trigger_reset_populate() def del_task(self): pass class todoapp(app): def build(self): return todoroot() if __name__ == '__main__': todoapp().run() and kv file: #: import main todo #: import listadapter kivy.adapters.listadapter.listadapter #: import listitembutton kivy.uix.listview.listitembutton todoroot: <todoroot>: orientation: "vertical" task_input: task_input_view t...
Read more

ruby - How do I merge two hashes into a hash of arrays? -

http://codepad.org/wmyzqlis i'd merge these 2 arrays: a = { :a => 'a', :b => 'b', :d => 'd' } b = { :a => '1', :b => 'b', :c => 'c' } into hash looks this: {:a => ["a", "1"], :b => ["b", "b"], :c => [nil, "c"], :d => ["d", nil] } this doesn't work: p a.merge(b) { |k, v1, v2| [v1, v2] } # {:c=>"c", :a=>["a", "1"], :b=>["b", "b"], :d=>"d"} it's because hash#merge call block duplicate keys. a = { :a => 'a', :b => 'b', :d => 'd' } b = { :a => '1', :b => 'b', :c => 'c' } hash[(a.keys|b.keys).map { |key| [key, [a.fetch(key, nil), b.fetch(key, nil)]] }] # => {:a=>["a", "1"], :b=>["b", "b"], :d=>["d", nil], :c=>...
Read more