By arunraj
Write an efficient algorithm to check whether a given number is prime or not.
public boolean isPrime(int n) {
if (n % 2 == 0)
return false;
for (int i = 3; i <= n / 2; i = i + 2) {
if (n % i == 0) {
return false;
} else {
if (i * i >= n) {
return true;
}
}
}
return true;
}
Also have a look at Java Prime Number
Interview Questions: