如何交换给定整数中的两位？

给定整数n和其中的两个比特位置p1和p2，在给定位置交换位。给定位置来自最低有效位(lsb)。例如，lsb的位置为0。
例子：

Input: n = 28, p1 = 0, p2 = 3
Output: 21
28 in binary is 11100.  If we swap 0'th and 3rd digits, 
we get 10101 which is 21 in decimal.

Input: n = 20, p1 = 2, p2 = 3
Output: 24

强烈建议您最小化浏览器，然后自己尝试。
方法1：
这个想法是首先找到这些位，然后使用基于XOR的交换概念，即交换两个数字’x’和’y’，我们做x = x ^ y，y = y ^ x和x = x ^ y。
下面是上述想法的实现

C++

// C++ program to swap bits in an integer
#include
using namespace std;
 
// This function swaps bit at positions p1 and p2 in an integer n
int swapBits(unsigned int n, unsigned int p1, unsigned int p2)
{
    /* Move p1'th to rightmost side */
    unsigned int bit1 =  (n >> p1) & 1;
 
    /* Move p2'th to rightmost side */
    unsigned int bit2 =  (n >> p2) & 1;
 
    /* XOR the two bits */
    unsigned int x = (bit1 ^ bit2);
 
    /* Put the xor bit back to their original positions */
    x = (x << p1) | (x << p2);
 
    /* XOR 'x' with the original number so that the
       two sets are swapped */
    unsigned int result = n ^ x;
}
 
/* Driver program to test above function*/
int main()
{
    int res =  swapBits(28, 0, 3);
    cout<<"Result = "<< res<<" ";
    return 0;
}
 
// This code is contributed by pratham76.

C

// C program to swap bits in an integer
#include
 
// This function swaps bit at positions p1 and p2 in an integer n
int swapBits(unsigned int n, unsigned int p1, unsigned int p2)
{
    /* Move p1'th to rightmost side */
    unsigned int bit1 =  (n >> p1) & 1;
 
    /* Move p2'th to rightmost side */
    unsigned int bit2 =  (n >> p2) & 1;
 
    /* XOR the two bits */
    unsigned int x = (bit1 ^ bit2);
 
    /* Put the xor bit back to their original positions */
    x = (x << p1) | (x << p2);
 
    /* XOR 'x' with the original number so that the
       two sets are swapped */
    unsigned int result = n ^ x;
}
 
/* Driver program to test above function*/
int main()
{
    int res =  swapBits(28, 0, 3);
    printf("Result = %d ", res);
    return 0;
}

Java

// Java program to swap bits in an integer
import java.io.*;
 
class GFG
{
     
// This function swaps bit at
// positions p1 and p2 in an integer n
static int swapBits( int n, int p1, int p2)
{
    /* Move p1'th to rightmost side */
    int bit1 = (n >> p1) & 1;
 
    /* Move p2'th to rightmost side */
    int bit2 = (n >> p2) & 1;
 
    /* XOR the two bits */
    int x = (bit1 ^ bit2);
 
    /* Put the xor bit back to
    their original positions */
    x = (x << p1) | (x << p2);
 
    /* XOR 'x' with the original
    number so that the
    two sets are swapped */
    int result = n ^ x;
    return result;
}
 
    /* Driver code*/
    public static void main (String[] args)
    {
        int res = swapBits(28, 0, 3);
        System.out.println ("Result = " + res);
    }
}
 
// This code is contributed by ajit..

C#

// C# program to swap bits in an integer
using System;
class GFG
{
 
  // This function swaps bit at
  // positions p1 and p2 in an integer n
  static int swapBits( int n, int p1, int p2)
  {
 
    /* Move p1'th to rightmost side */
    int bit1 = (n >> p1) & 1;
 
    /* Move p2'th to rightmost side */
    int bit2 = (n >> p2) & 1;
 
    /* XOR the two bits */
    int x = (bit1 ^ bit2);
 
    /* Put the xor bit back to
    their original positions */
    x = (x << p1) | (x << p2);
 
    /* XOR 'x' with the original
    number so that the
    two sets are swapped */
    int result = n ^ x;
    return result;
  }
 
  /* Driver code*/
  public static void Main(string[] args)
  {
    int res = swapBits(28, 0, 3);
    Console.Write("Result = " + res);
  }
}
 
// This code is contributed by rutvik_56.

Javascript

// javascript program to swap bits in an integer
 
     
// This function swaps bit at
// positions p1 and p2 in an integer n
function swapBits(n , p1 , p2)
{
    /* Move p1'th to rightmost side */
    var bit1 = (n >> p1) & 1;
 
    /* Move p2'th to rightmost side */
    var bit2 = (n >> p2) & 1;
 
    /* XOR the two bits */
    var x = (bit1 ^ bit2);
 
    /* Put the xor bit back to
    their original positions */
    x = (x << p1) | (x << p2);
 
    /* XOR 'x' with the original
    number so that the
    two sets are swapped */
    var result = n ^ x;
    return result;
}
 
/* Driver code*/
var res = swapBits(28, 0, 3);
document.write("Result = " + res);
 
 
// This code contributed by Princi Singh

输出

Result = 21 

C++

//C++ code for swapping given bits of a number
#include
using namespace std;
int swapBits(int n, int p1, int p2)
{
    //left-shift 1 p1 and p2 times
    //and using XOR
    n ^= 1 << p1;
    n ^= 1 << p2;
    return n;
}
 
//Driver Code
int main()
{
    cout << "Result = " << swapBits(28, 0, 3);
    return 0;
}
 
//This code is contributed by yashbeersingh42

C

//C code for swapping given bits of a number
#include
int swapBits(int n, int p1, int p2)
{
    //left-shift 1 p1 and p2 times
    //and using XOR
    n ^= 1 << p1;
    n ^= 1 << p2;
    return n;
}
 
//Driver Code
int main()
{
    printf("Result = %d", swapBits(28, 0, 3));
    return 0;
}
 
//This code is contributed by yashbeersingh42

Java

// Java code for swapping
// given bits of a number
import java.util.*;
class Main{
   
public static int swapBits(int n,
                           int p1,
                           int p2)
{
  //left-shift 1 p1 and
  // p2 times and using XOR
  n ^= 1 << p1;
  n ^= 1 << p2;
  return n;
}   
 
// Driver code
public static void main(String[] args)
{
  System.out.print("Result = " +
                   swapBits(28, 0, 3));
}
}
 
// This code is contributed by divyeshrabadiya07

Python

# Python code for swapping given bits of a number
def swapBits(n, p1, p2):
 
  # left-shift 1 p1 and p2 times
  # and using XOR
  n ^= 1 << p1
  n ^= 1 << p2
  return n
 
# Driver Code
print("Result =",swapBits(28, 0, 3))
 
# This code is contributed by rag2127

C＃

// C# code for swapping given bits of a number
using System;
class GFG {
 
  static int swapBits(int n, int p1, int p2)
  {
    // left-shift 1 p1 and p2 times
    // and using XOR
    n ^= 1 << p1;
    n ^= 1 << p2;
    return n;
  }
 
  // Driver code
  static void Main() {
    Console.WriteLine("Result = " + swapBits(28, 0, 3));
  }
}
 
// This code is contributed by divyesh072019

Java脚本

 
    // JavaScript code for swapping given bits of a number
     
    function swapBits(n, p1, p2)
    {
        //left-shift 1 p1 and p2 times
        //and using XOR
        n ^= 1 << p1;
        n ^= 1 << p2;
        return n;
    }
 
    document.write("Result = " + swapBits(28, 0, 3));
     

输出

Result = 21