Re: Re: easiest way to sort a list?
- To: mathgroup at smc.vnet.net
- Subject: [mg18338] Re: [mg18320] Re: [mg18308] easiest way to sort a list?
- From: "Tomas Garza" <tgarza at mail.internet.com.mx>
- Date: Sun, 27 Jun 1999 15:11:24 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Both methods suggested by ARNOLDK [arnoldk at gauss.cam.wits.ac.za]work fine.
However, the use of ReplaceRepeated takes an inordinate amount of time. Any
idea why?
In[1]:=
myNumbers = Table[Random[Integer, {1, 99}], {500}];
myNumbers //. {a___, b_, c___, b_, d___} -> {a, b, c, d}; // Timing
Out[2]=
{46.52 Second, Null}
In[3]:=
union2[l_] :=
Fold[Flatten[If[! MemberQ[#1, #2], Append[#1, #2], #1]] &, {}, l]
In[4]:=
union2[myNumbers]; // Timing
Out[4]=
{0.06 Second, Null}
Tomas Garza
Mexico City