Merge pull request TheAlgorithms#939 from 0Zeta/0zeta/prime-check-cor…

…rection Correct prime check
jonneyzhang · Oct 2, 2019 · b8b2938 · b8b2938
2 parents 5d77b08 + 2f62929
commit b8b2938
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/Maths/PrimeCheck.java b/Maths/PrimeCheck.java
@@ -21,6 +21,12 @@ public static void main(String[] args) {
      * @return {@code true} if {@code n} is prime
      */
     public static boolean isPrime(int n) {
+        if (n == 2) {
+            return true;
+        }
+        if (n < 2 || n % 2 == 0) {
+            return false;
+        }
         for (int i = 3; i <= Math.sqrt(n); i += 2) {
             if (n % i == 0) {
                 return false;