Re: Find the sum of all the prime numbers
There is other method also which does not require sqrt.
Quote:

Re: Find the sum of all the prime numbers
Interesting, so we will find the factor of n within any of the number in sqrt(n) if not then its a prime number.

Re: Find the sum of all the prime numbers
let me tell you the logic now
it is very simple look if k is any no. then k can be represented as k=i*j where i and are k's factor now i varies from 1to k and j varies from k to 1 but for prime no. we check for i=2 to k/2 acordingly j will varies from (k/2) to 2 now if 2 is a factor of k then automatically k/2 is also a factor and so on that is when i increases, j decreases so we continue like this then there is condition that both i and j becomes equal so i*i=k so i=sqrt(k) but if k is not a square of any no. then i increases upto a integer just less than sqrt iof k thats all what i did now try this problem for a given no. print all its prime factors that is if input is 12 out put should be 2*2*3 using the hint that the lowest factor of any no. other than one is always prime try it 
Re: Find the sum of all the prime numbers
friendsforniraj thats a good logic explained.

Re: Find the sum of all the prime numbers
thank u sir
but ma name is niraj 
Re: Find the sum of all the prime numbers
Quote:

Re: Find the sum of all the prime numbers
why do we need a square root

Re: Find the sum of all the prime numbers
Quote:

Re: Find the sum of all the prime numbers
for(j=2;j<=sqrt(i);j++) :cryin:
is similar to for(j=2;j*j <= i;j++) :p so, no sqrt in here since it is really slow. At least if was some years ago. 
Re: Find the sum of all the prime numbers
for getting the prime number try
http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes No devisions in here 
All times are GMT +5.5. The time now is 09:23. 