upd

9. Palindrome Number/Solution.java

@@ -0,0 +1,16 @@
+class Solution {
+    public static void main(String[] args) {
+      int test[] = {121, -121, 10};
+
+      for (int t : test) {
+        System.out.println("isPalindrome(" + t + ") = " + isPalindrome(t));
+      }
+    }
+
+    public static boolean isPalindrome(int x) {
+      StringBuilder sb = new StringBuilder(Integer.toString(x));
+      sb.reverse();
+      String reversed = sb.toString();
+      return Integer.toString(x).equals(reversed);
+    }
+}