Question5_6.java

/**
 * Write a program to swap odd and even bits in an integer with as few instructions as possible
 * (e.g., bit 0 and bit 1 are swapped, bit 2 and bit 3 are swapped, and so on).
 * 
 * Time  Complexity: O(1)
 * Space Complexity: O(1)
 */

public class Question5_6 {
    public int swapBits(int value) {
        return ((value & 0x55555555) << 1) | ((value & 0xAAAAAAAA) >> 1);
    }
    
    
    public static void main(String[] args) {
        Question5_6 question5_6 = new Question5_6();
        System.out.println(Integer.toBinaryString(question5_6.swapBits(0b1100)));
        System.out.println(Integer.toBinaryString(question5_6.swapBits(0b1110)));
        System.out.println(Integer.toBinaryString(question5_6.swapBits(0b1010)));
        System.out.println(Integer.toBinaryString(question5_6.swapBits(0)));
    }
}