Add HigherLowerPowerOfTwo algorithm (#5707)

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

@@ -0,0 +1,54 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * HigherLowerPowerOfTwo class has two methods to find the next higher and lower power of two.
+ * <p>
+ *     nextHigherPowerOfTwo method finds the next higher power of two.
+ *     nextLowerPowerOfTwo method finds the next lower power of two.
+ *     Both methods take an integer as input and return the next higher or lower power of two.
+ *     If the input is less than 1, the next higher power of two is 1.
+ *     If the input is less than or equal to 1, the next lower power of two is 0.
+ *     nextHigherPowerOfTwo method uses bitwise operations to find the next higher power of two.
+ *     nextLowerPowerOfTwo method uses Integer.highestOneBit method to find the next lower power of two.
+ *     The time complexity of both methods is O(1).
+ *     The space complexity of both methods is O(1).
+ * </p>
+ *
+ * @author Hardvan
+ */
+public final class HigherLowerPowerOfTwo {
+    private HigherLowerPowerOfTwo() {
+    }
+
+    /**
+     * Finds the next higher power of two.
+     *
+     * @param x The given number.
+     * @return The next higher power of two.
+     */
+    public static int nextHigherPowerOfTwo(int x) {
+        if (x < 1) {
+            return 1;
+        }
+        x--;
+        x |= x >> 1;
+        x |= x >> 2;
+        x |= x >> 4;
+        x |= x >> 8;
+        x |= x >> 16;
+        return x + 1;
+    }
+
+    /**
+     * Finds the next lower power of two.
+     *
+     * @param x The given number.
+     * @return The next lower power of two.
+     */
+    public static int nextLowerPowerOfTwo(int x) {
+        if (x < 1) {
+            return 0;
+        }
+        return Integer.highestOneBit(x);
+    }
+}