Discussion on Prime Checker Challenge

[deleted] 3 years ago+ 1 comment

Can improve

for (int i = 2; i < (num/2)+1; i++){
            if (num%i==0){
                return false;
            }
        }

for (int i = 2; i*i <= num; i++){
            if (num%i==0){
                return false;
            }
        }

will be faster

vlad_belon 3 years ago+ 0 comments

To avoid the i*i calculus in each loop:

long maxDivider = Math.round(Math.sqrt(number));
for (int divider = 2; divider <= maxDivider; divider++) {
	if (number % divider == 0) {
		return false;
	}
}