Skip to content
Related Articles

Related Articles

C++ Program to Rotate bits of a number

View Discussion
Improve Article
Save Article
  • Last Updated : 11 Dec, 2021

Bit Rotation: A rotation (or circular shift) is an operation similar to shift except that the bits that fall off at one end are put back to the other end. 
In left rotation, the bits that fall off at left end are put back at right end. 
In right rotation, the bits that fall off at right end are put back at left end.
 

Example: 
Let n is stored using 8 bits. Left rotation of n = 11100101 by 3 makes n = 00101111 (Left shifted by 3 and first 3 bits are put back in last ). If n is stored using 16 bits or 32 bits then left rotation of n (000…11100101) becomes 00..0011100101000. 
Right rotation of n = 11100101 by 3 makes n = 10111100 (Right shifted by 3 and last 3 bits are put back in first ) if n is stored using 8 bits. If n is stored using 16 bits or 32 bits then right rotation of n (000…11100101) by 3 becomes 101000..0011100
 

C++




// C++ code to rotate bits 
// of number
#include<iostream>
  
using namespace std;
#define INT_BITS 32
class gfg
{
      
/*Function to left rotate n by d bits*/
public:
int leftRotate(int n, unsigned int d)
{
      
    /* In n<<d, last d bits are 0. To
     put first 3 bits of n at 
    last, do bitwise or of n<<d 
    with n >>(INT_BITS - d) */
    return (n << d)|(n >> (INT_BITS - d));
}
  
/*Function to right rotate n by d bits*/
int rightRotate(int n, unsigned int d)
{
    /* In n>>d, first d bits are 0. 
    To put last 3 bits of at 
    first, do bitwise or of n>>d
    with n <<(INT_BITS - d) */
    return (n >> d)|(n << (INT_BITS - d));
}
};
  
/* Driver code*/
int main()
{
    gfg g;
    int n = 16;
    int d = 2;
    cout << "Left Rotation of " << n << 
            " by " << d << " is ";
    cout << g.leftRotate(n, d);
    cout << "
Right Rotation of " << n <<
            " by " << d << " is ";
    cout << g.rightRotate(n, d);
    getchar();
  
// This code is contributed by SoM15242


Output : 

Left Rotation of 16 by 2 is 64
Right Rotation of 16 by 2 is 4

Please refer complete article on Rotate bits of a number for more details!


My Personal Notes arrow_drop_up
Recommended Articles
Page :

Start Your Coding Journey Now!