That was also my first reaction, but merlyn's algorithm is lightening fast. As is often the case, one trades speed for memory. On modern computers the amount of memory needed to find primes between 1 and 1 million is rarely an issue. The OP is satisfied with the primes < 1 million. If you are looking for very, very large primes (10's of digits) I'm sure other slower algorithms might be better.

Best, beth

In reply to Re^3: Find prime number between 1 to 1000000 by ELISHEVA
in thread Find prime number between 1 to 1000000 by mecrazycoder

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