isPrime, Naive Version

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bool isPrime0( int x ) { for( int divisor = 2; divisor < x; divisor++ ) { if( x % divisor == 0 ) { return false; } } return true; }

Other entries:

• isPrime: Naive version 
• isPrime, Optimization 1: Iterate only until the square root of the number
• isPrime, Optimization 2: Only divide by odd numbers, until the square root of the number
• isPrime, Optimization 3: Skip the divisors that are multiple of 2 or 3
• Keep the previosly generated primes and use them to test the following numbers.
• isPrime, Recursive.