Re: fastest way to add up a billion numbers

*To*: mathgroup at smc.vnet.net*Subject*: [mg73923] Re: [mg73880] fastest way to add up a billion numbers*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Sat, 3 Mar 2007 01:03:40 -0500 (EST)*References*: <200703021141.GAA04040@smc.vnet.net>

On 2 Mar 2007, at 12:41, Raj wrote: > hi! > > Could somebody tell me what would be the fastest way to add up a > billion numbers(from 1 to 10^9 i.e the first billion numbers) in > Mathematica? > > Ofcourse the answer is n(n+1)/2, but is there any other way in > Mathematica other than the following one: > > Total@@Range[10^9] > > Thanks, > > Raj > > Sum[i,{i,1,10^9}]//Timing {0.122547 Second,500000000500000000} or much faster In[3]:= Timing[NSum[i, {i, 1, 10^9}]] Out[3]= {0.0021539999999999893*Second, 5.000000005*^17} ANdrzej Kozlowski

**References**:**fastest way to add up a billion numbers***From:*"Raj" <rajanikanth@gmail.com>