📜  程序来切换数字N的第K位

📅  最后修改于: 2021-05-25 00:41:23             🧑  作者: Mango

给定数字N,任务是清除此数字N的第K位。如果第K位为0,则将其设置为1,如果为1,则将其设置为0。

例子:

Input: N = 5, K = 2
Output: 7
5 is represented as 101 in binary
and has its second bit 0, so toggling
it will result in 111 i.e. 7.

Input: N = 5, K = 1
Output: 4
5 is represented as 101 in binary
and has its first bit is 1, so toggling
it will result in 100 i.e. 4.

方法:

  • 由于未设置位和设置位的XOR会导致设置位,而已设置位和设置位的XOR会导致未设置位。因此,用设置的位对任何位执行按位XOR运算将导致该位的切换,即
    Any bit  Set bit = Toggle
    
    which means,
    0 ^ 1 = 1
    1 ^ 1 = 0
    
    
    
        
  • 因此,为了切换一位,最好将数字与复位位进行按位异或。
    n = n ^ 1 << k
    OR
    n ^= 1 << k
    
    where k is the bit that is to be cleared
    

下面是上述方法的实现:

C
// C program to toggle K-th bit of a number N
  
#include 
  
// Function to toggle the kth bit of n
int toggleBit(int n, int k)
{
    return (n ^ (1 << (k - 1)));
}
  
// Driver code
int main()
{
    int n = 5, k = 2;
  
    printf("%d\n", toggleBit(n, k));
  
    return 0;
}


Java
// Java program to toggle K-th bit of a number N
class GFG
{
  
// Function to toggle the kth bit of n
static int toggleBit(int n, int k)
{
    return (n ^ (1 << (k - 1)));
}
  
// Driver code
public static void main(String []args)
{
    int n = 5, k = 2;
  
    System.out.printf("%d\n", toggleBit(n, k));
}
}
  
// This code is contributed by Rajput-Ji


Python3
# Python3 program to clear K-th bit 
# of a number N 
  
# Function to toggle the kth bit of n 
def toggleBit(n, k) :
  
    return (n ^ (1 << (k - 1))); 
  
# Driver code 
if __name__ == "__main__" : 
  
    n = 5; k = 2; 
  
    print(toggleBit(n, k));
  
# This code is contributed by AnkitRai01


C#
// C# program to toggle K-th bit of a number N
using System; 
  
class GFG
{
  
// Function to toggle the kth bit of n
static int toggleBit(int n, int k)
{
    return (n ^ (1 << (k - 1)));
}
  
// Driver code
public static void Main(String []args)
{
    int n = 5, k = 2;
  
    Console.WriteLine("{0}", toggleBit(n, k));
}
}
  
// This code is contributed by PrinciRaj1992


输出:
7