如何从数字中给定位置“ p”中提取“ k”位?
例子:
Input : number = 171
k = 5
p = 2
Output : The extracted number is 21
171 is represented as 0101011 in binary,
so, you should get only 10101 i.e. 21.
Input : number = 72
k = 5
p = 1
Output : The extracted number is 8
72 is represented as 1001000 in binary,
so, you should get only 01000 i.e 8.
1)右移数字p-1。
2)用修改后的数字对k个设置位进行按位与运算。我们可以通过(1 << k)– 1来获得k个设置位。
C
// C program to extract k bits from a given
// position.
#include
// Function to extract k bits from p position
// and returns the extracted value as integer
int bitExtracted(int number, int k, int p)
{
return (((1 << k) - 1) & (number >> (p - 1)));
}
// Driver code
int main()
{
int number = 171, k = 5, p = 2;
printf("The extracted number is %d",
bitExtracted(number, k, p));
return 0;
}
Java
// Java program to extract k bits from a given
// position.
class GFG {
// Function to extract k bits from p position
// and returns the extracted value as integer
static int bitExtracted(int number, int k, int p)
{
return (((1 << k) - 1) & (number >> (p - 1)));
}
// Driver code
public static void main (String[] args) {
int number = 171, k = 5, p = 2;
System.out.println("The extracted number is "+
bitExtracted(number, k, p));
}
}
Python
# Python program to extract k bits from a given
# position.
# Function to extract k bits from p position
# and returns the extracted value as integer
def bitExtracted(number, k, p):
return ( ((1 << k) - 1) & (number >> (p-1) ) );
# number is from where 'k' bits are extracted
# from p position
number = 171
k = 5
p = 2
print "The extracted number is ", bitExtracted(number, k, p)
C#
// C# program to extract k bits from a given
// position.
using System;
class GFG {
// Function to extract k bits from p position
// and returns the extracted value as integer
static int bitExtracted(int number, int k, int p)
{
return (((1 << k) - 1) & (number >> (p - 1)));
}
// Driver code
public static void Main()
{
int number = 171, k = 5, p = 2;
Console.WriteLine("The extracted number is "
+ bitExtracted(number, k, p));
}
}
//This code is contributed by Anant Agarwal.
PHP
> ($p - 1)));
}
// Driver Code
$number = 171; $k = 5; $p = 2;
echo "The extracted number is ",
bitExtracted($number, $k, $p);
// This code is contributed by Ajit
?>
Javascript
输出 :
The extracted number is 21