Create PalindromeNumber.java

Author: techieJarek

PalindromeNumber.java

@@ -0,0 +1,25 @@
+/**
+ * Determine whether an integer is a palindrome. Do this without extra space.
+ */
+public class PalindromeNumber {
+    public static void main(String[] args){
+        System.out.println("1234321 is palindrome = " + isPalindrome(1234321));
+        System.out.println("1234567 is palindrome = " + isPalindrome(1234567));
+    }
+
+    private static boolean isPalindrome(int num) {
+        int div = 1;
+        while(num / div > 10){
+            div*=10;
+        }
+
+        while(num != 0){
+            int r = num % 10;
+            int l = num / div;
+            if(r != l) return false;
+            num = (num % div) / 10;
+            div /= 100;
+        }
+        return true;
+    }
+}