diff --git a/N_Prime_Numbers b/N_Prime_Numbers new file mode 100644 index 0000000..69ec3ca --- /dev/null +++ b/N_Prime_Numbers @@ -0,0 +1,31 @@ +# Python program to print all primes smaller than or equal to +# n using Sieve of Eratosthenes + +def SieveOfEratosthenes(n): + + # Create a boolean array "prime[0..n]" and initialize + # all entries it as true. A value in prime[i] will + # finally be false if i is Not a prime, else true. + prime = [True for i in range(n+1)] + p = 2 + while (p * p <= n): + + # If prime[p] is not changed, then it is a prime + if (prime[p] == True): + + # Update all multiples of p + for i in range(p * p, n+1, p): + prime[i] = False + p += 1 + + # Print all prime numbers + for p in range(2, n+1): + if prime[p]: + print p, + +# driver program +if __name__=='__main__': + n = 30 + print "Following are the prime numbers smaller", + print "than or equal to", n + SieveOfEratosthenes(n)