Add GrayCodeConversion algorithm (#5705)

src/main/java/com/thealgorithms/bitmanipulation/GrayCodeConversion.java

@@ -0,0 +1,44 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * Gray code is a binary numeral system where two successive values differ in only one bit.
+ * This is a simple conversion between binary and Gray code.
+ * Example:
+ * 7 -> 0111 -> 0100 -> 4
+ * 4 -> 0100 -> 0111 -> 7
+ * 0 -> 0000 -> 0000 -> 0
+ * 1 -> 0001 -> 0000 -> 0
+ * 2 -> 0010 -> 0011 -> 3
+ * 3 -> 0011 -> 0010 -> 2
+ *
+ * @author Hardvan
+ */
+public final class GrayCodeConversion {
+    private GrayCodeConversion() {
+    }
+
+    /**
+     * Converts a binary number to Gray code.
+     *
+     * @param num The binary number.
+     * @return The corresponding Gray code.
+     */
+    public static int binaryToGray(int num) {
+        return num ^ (num >> 1);
+    }
+
+    /**
+     * Converts a Gray code number back to binary.
+     *
+     * @param gray The Gray code number.
+     * @return The corresponding binary number.
+     */
+    public static int grayToBinary(int gray) {
+        int binary = gray;
+        while (gray > 0) {
+            gray >>= 1;
+            binary ^= gray;
+        }
+        return binary;
+    }
+}