Added tests

Author: javadev

src/test/java/g3601_3700/s3677_count_binary_palindromic_numbers/SolutionTest.java

@@ -15,4 +15,45 @@ void countBinaryPalindromes() {
     void countBinaryPalindromes2() {
         assertThat(new Solution().countBinaryPalindromes(9L), equalTo(6));
     }
+
+    @Test
+    void countBinaryPalindromes3() {
+        // Branch: n == 0 → returns 1 immediately
+        assertThat(new Solution().countBinaryPalindromes(0), equalTo(1));
+    }
+
+    @Test
+    void countBinaryPalindromes4() {
+        // n = 1 ("1") → palindrome
+        // Expected palindromes: 1 (0) + 1 (1) = 2
+        assertThat(new Solution().countBinaryPalindromes(1), equalTo(2));
+    }
+
+    @Test
+    void countBinaryPalindromes5() {
+        // n = 6 ("110"), length = 3 (odd)
+        // Palindromes up to 6: 0,1,3,5
+        assertThat(new Solution().countBinaryPalindromes(6), equalTo(4));
+    }
+
+    @Test
+    void countBinaryPalindromes6() {
+        // n = 9 ("1001"), palindrome itself
+        // Palindromes up to 9: 0,1,3,5,7,9
+        assertThat(new Solution().countBinaryPalindromes(9), equalTo(6));
+    }
+
+    @Test
+    void countBinaryPalindromes7() {
+        // n = 10 ("1010") → next palindrome = 9 (smaller) → branch where palin <= n
+        // Palindromes up to 10: 0,1,3,5,7,9
+        assertThat(new Solution().countBinaryPalindromes(10), equalTo(6));
+    }
+
+    @Test
+    void countBinaryPalindromes8() {
+        // 1023 = "1111111111"
+        long n = (1L << 10) - 1;
+        assertThat(new Solution().countBinaryPalindromes(n), equalTo(63));
+    }
 }