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GeneralRe: Specify numbers as product of Primes? PinmemberChandraRam2-Jul-08 22:49 
GeneralRe: Specify numbers as product of Primes? PinmemberMarkBrock2-Jul-08 23:06 
AnswerRe: Specify numbers as product of Primes? PinmemberMember 419459326-Jun-08 8:19 
GeneralRe: Specify numbers as product of Primes? PinmemberRobert.C.Cartaino26-Jun-08 8:47 
GeneralRe: Specify numbers as product of Primes? PinmemberIan Uy26-Jun-08 17:51 
GeneralRe: Specify numbers as product of Primes? Pinmembercp987629-Jun-08 14:57 
AnswerRe: Specify numbers as product of Primes? PinmemberArash Partow29-Jun-08 0:48 
GeneralRe: Specify numbers as product of Primes? [modified] Pinmembercp987629-Jun-08 3:53 
[edit] since Arash has completely changed the code in his previous post, this appears somewhat out of context [/edit]
 
I think this is an example of misguided optimization. Whilst Ian Uy's example looks inefficient
 
int main()
{	
int InputCase;	
cin >> InputCase;
for(int i=2;i<=InputCase;i++)
   {
   if(InputCase%i==0)
      {
      cout << i;
      InputCase/=i;
      i--;
      }
   }
return 0;
}
 
all he is doing each iteration is testing
 
   if(InputCase%i==0)
 
In order to avoid these "unnecessary" tests, you are testing each n as
 
   if (n % 2 == 0) n++;   
   while(!is_prime(n)) { ++n; } 
 
The function is_prime(n) will involve much more overhead than the original code, and it doesn't matter that 'i' may not be prime.
 
Peter
"Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
modified on Saturday, October 18, 2008 11:35 PM

GeneralRe: Specify numbers as product of Primes? PinmvpLuc Pattyn29-Jun-08 4:40 
GeneralRe: Specify numbers as product of Primes? Pinmembercp987629-Jun-08 14:47 
GeneralRe: Specify numbers as product of Primes? PinmemberArash Partow30-Jun-08 2:54 
GeneralRe: Specify numbers as product of Primes? Pinmembercp987630-Jun-08 3:18 
GeneralRe: Specify numbers as product of Primes? PinmemberArash Partow30-Jun-08 4:27 
GeneralRe: Specify numbers as product of Primes? PinmemberArash Partow30-Jun-08 2:17 
Questionlogic of prob function in ms excel Pinmembersumit703425-Jun-08 0:40 
QuestionFactorials PinmemberIan Uy24-Jun-08 8:17 
AnswerRe: Factorials PinmemberTim Craig24-Jun-08 10:29 
GeneralRe: Factorials PinmemberIan Uy25-Jun-08 6:32 
GeneralRe: Factorials PinmemberTim Craig25-Jun-08 8:55 
GeneralRe: Factorials PinmvpLuc Pattyn25-Jun-08 11:01 
GeneralRe: Factorials PinmemberTim Craig25-Jun-08 21:06 
AnswerRe: Factorials Pinmembercp987624-Jun-08 12:33 
AnswerRe: Factorials PinmemberMatthew Butler24-Jun-08 12:38 
GeneralRe: Factorials Pinmembercp987624-Jun-08 14:05 
GeneralRe: Factorials PinmvpLuc Pattyn24-Jun-08 15:02 

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