计算模数除以2的幂

在不使用除法(/)和模数(％)运算符的情况下计算n模d，其中d是2的幂。
从右起第i位设置为d。为了获得n模数d，我们只需要按原样返回0到i -1(从右)的n位，其他位返回0。
例如，如果n = 6(00..110)和d = 4(00..100)。 d中的最后一个设置位在位置3(从右侧)。因此，我们需要按原样返回n的最后两位，其他位返回0，即00..010。
现在做起来非常容易，猜出来……。
是的，您猜对了。请参阅以下程序。

C++

#include
 
// This function will return n % d.
// d must be one of: 1, 2, 4, 8, 16, 32, …
unsigned int getModulo(unsigned int n,
                       unsigned int d)
{
return ( n & (d - 1) );
}        
 
// Driver Code
int main()
{
unsigned int n = 6;
 
// d must be a power of 2
unsigned int d = 4;
printf("%u moduo %u is %u", n, d, getModulo(n, d));
 
getchar();
return 0;
}

Java

// Java code for Compute modulus division by
// a power-of-2-number
class GFG {
     
    // This function will return n % d.
    // d must be one of: 1, 2, 4, 8, 16, 32,
    static int getModulo(int n, int d)
    {
        return ( n & (d-1) );
    }    
     
    // Driver Code
    public static void main(String[] args)
    {
        int n = 6;
         
        /*d must be a power of 2*/
        int d = 4;
         
        System.out.println(n+" moduo " + d +
                    " is " + getModulo(n, d));
    }
}
 
// This code is contributed
// by Smitha Dinesh Semwal.

Python3

# Python code to demonstrate
# modulus division by power of 2
 
 
# This function will
# return n % d.
# d must be one of:
# 1, 2, 4, 8, 16, 32, …
def getModulo(n, d):
 
    return ( n & (d-1) )
          
# Driver program to
# test above function
n = 6
 
#d must be a power of 2
d = 4
print(n,"moduo",d,"is",
      getModulo(n, d))
 
# This code is contributed by
# Smitha Dinesh Semwal

C#

// C# code for Compute modulus
// division by a power-of-2-number
using System;
 
class GFG {
     
// This function will return n % d.
// d must be one of: 1, 2, 4, 8, 16, 32, …
static uint getModulo( uint n, uint d)
{
return ( n & (d-1) );
}    
 
// Driver code
static public void Main ()
   {
    uint n = 6;
    uint d = 4; /*d must be a power of 2*/
 
    Console.WriteLine( n + " moduo " + d +
                " is " + getModulo(n, d));
     
    }
}
// This code is contributed by vt_m.

Javascript

// This function will return n % d.
// d must be one of: 1, 2, 4, 8, 16, 32, …
function getModulo(n,d)
{
    return ( n & (d - 1) );
}        
   
// Driver Code
 n = 6;
 d = 4;
  
document.write(n  +" moduo "+ d + " is "+ getModulo(n, d));
 
  // This code is contributed by simranarora5sos

https://www.youtube.com/watch?v=fSjW

-wDghTs