将M插入N，以使m从第j位开始，到第i |位结束。套装2

给定两个32位数字N和M，以及两个位置i和j。编写一种将M插入N的方法，以使M从第j位开始，到第i位结束。您可以假设j到i位有足够的空间来容纳所有M。假定索引从0开始。

例子：

a)  N = 1024 (10000000000),
    M = 19 (10011),
    i = 2, j = 6 
    Output : 1100 (10001001100)
b)  N = 1201 (10010110001)
    M = 8 (1000)
    i = 3, j = 6
    Output: 1217 (10011000001)

在上一篇文章中已经讨论了这个问题。在这篇文章中，讨论了一种不同的方法。
方法：这个想法很简单，下面是逐步过程–

• 捕获N中i之前的所有位，即从i-1到0。
• 我们不想更改这些位，因此我们将捕获它们并在以后使用
• 清除从j到0的所有位
• 在位置i到i的N处将M插入
• 将捕获的位插入相应的位置，即。从i-1到0

让我们尝试解决示例b，以清楚地说明该过程。

在N中捕获i-1至0位

创建一个掩码，其i-1至0位为1，其余均为0。将1移至i的左侧，并从中减去1，以获得设置了i-1至0位的位掩码。

capture_mask = ( 1 << i ) - 1  

因此，例如b，遮罩将为–

capture_mask = ( 1 << 3 ) - 1 
Now capture_mask = 1(001)

现在，与该具有N的掩码，i-1至0位将保持不变，而其余位变为0。因此，我们只剩下i-1至0位。

captured_bits = N & capture_mask

例如，b，捕获的位将是–

captured_bits = N & capture_mask
Now capture_mask = 1 (001)

清除N中从j到0的位

由于已捕获位，因此将位j清除为0而不丢失位i-1到0。创建一个掩码，使其j到0的位为0，其余的为1。通过在其中将-1移至j + 1来创建此掩码。左边。

clear_mask = -1 << ( j + 1 )

现在将j清除为0，并用N掩码。

N  &= clear_mask 

例如b将是：

N &= clear_mask 
Now N = 1152 (10010000000)

在N中插入M

现在由于N已清除了从j到0的位，因此只需将M装入N并将M i的位置向左移动，以将M的MSB与N中的位置j对齐。

M <<= i

例如b-

M <<= 3
Now M = 8 << 3 = 64 (1000000)

对M与N进行“或”运算以将M插入所需的位置。

N |= M

例如b –

N |= M 
Now N = 1152 | 64 = 1216 (10011000000)

将捕获的位插入N

到现在为止，已经将M插入到N中。现在剩下的唯一事情是将位置i-1处的捕获位合并回去。这可以简单地通过对N和捕获位进行OR来完成–

N |= captured_bits

例如b –

N |= captured_bits
N = 1216 | 1 = 1217 (10011000001)

因此，最终在插入之后，获得了以下位集。

N(before) = 1201 (10010110001)
N(after) = 1201 (10011000001)

下面是上述方法的实现：

C++

// C++ program to insert 32-bit number
// M into N using bit magic
#include 
using namespace std;
  
// print binary representation of n
void bin(unsigned n)
{
    if (n > 1)
        bin(n / 2);
    printf("%d", n % 2);
}
  
// Insert m into n
int insertion(int n, int m, int i, int j)
{
    int clear_mask = -1 << (j + 1);
    int capture_mask = (1 << i) - 1;
  
    // Capturing bits from i-1 to 0
    int captured_bits = n & capture_mask;
  
    // Clearing bits from j to 0
    n &= clear_mask;
  
    // Shiftng m to align with n
    m = m << i;
  
    // Insert m into n
    n |= m;
  
    // Insert captured bits
    n |= captured_bits;
  
    return n;
}
  
// Driver Code
int main()
{
  
    // print original bitset
    int N = 1201, M = 8, i = 3, j = 6;
    cout << "N = " << N << "(";
    bin(N);
    cout << ")"
         << "\n";
  
    // print original bitset
    cout << "M = " << M << "(";
    bin(M);
    cout << ")"
         << "\n";
  
    // Call function to insert M to N
    N = insertion(N, M, i, j);
    cout << "After inserting M into N from 3 to 6"
         << "\n";
  
    // Print the inserted bitset
    cout << "N = " << N << "(";
    bin(N);
    cout << ")"
         << "\n";
    return 0;
}

Java

// Java program to insert
// 32-bit number M into N
// using bit magic
import java.io.*;
  
class GFG
{
      
// print binary 
// representation of n
static void bin(long n)
{
    if (n > 1)
        bin(n / 2);
    System.out.print(n % 2);
}
  
// Insert m into n
static int insertion(int n, int m, 
                     int i, int j)
{
    int clear_mask = -1 << (j + 1);
    int capture_mask = (1 << i) - 1;
  
    // Capturing bits from i-1 to 0
    int captured_bits = n & capture_mask;
  
    // Clearing bits from j to 0
    n &= clear_mask;
  
    // Shiftng m to align with n
    m = m << i;
  
    // Insert m into n
    n |= m;
  
    // Insert captured bits
    n |= captured_bits;
  
    return n;
}
  
// Driver Code
public static void main (String[] args) 
{
    // print original bitset
    int N = 1201, M = 8, i = 3, j = 6;
    System.out.print("N = " + N + "(");
    bin(N);
    System.out.println(")");
      
    // print original bitset
    System.out.print("M = " + M + "(");
    bin(M);
    System.out.println(")");
      
    // Call function to insert M to N
    N = insertion(N, M, i, j);
    System.out.println( "After inserting M " + 
                        "into N from 3 to 6");
      
    // Print the inserted bitset
    System.out.print("N = " + N + "(");
    bin(N);
    System.out.println(")");
}
}
  
// This code is contributed 
// by inder_verma.

Python3

# Python 3 program to insert 32-bit number 
# M into N using bit magic
  
# insert M into N
def insertion(n, m, i, j):
  
    clear_mask = -1 << (j + 1)
    capture_mask = (1 << i) - 1
  
    # Capturing bits from i-1 to 0
    captured_bits = n & capture_mask 
  
    # Clearing bits from j to 0
    n &= clear_mask
  
    # Shiftng m to align with n
    m = m << i
  
    # Insert m into n
    n |= m 
  
    # Insert captured bits
    n |= captured_bits
  
    return n
  
# Driver
def main():
    N = 1201; M = 8; i = 3; j = 6
    print("N = {}({})".format(N, bin(N)))
    print("M = {}({})".format(M, bin(M)))
    N = insertion(N, M, i, j)
    print("***After inserting M into N***")
    print("N = {}({})".format(N, bin(N)))
  
if __name__ == '__main__':
    main()

C#

// C# program to insert
// 32-bit number M into N
// using bit magic
using System;
  
class GFG
{
      
// print binary 
// representation of n
static void bin(long n)
{
    if (n > 1)
        bin(n / 2);
    Console.Write(n % 2);
}
  
// Insert m into n
static int insertion(int n, int m, 
                     int i, int j)
{
    int clear_mask = -1 << (j + 1);
    int capture_mask = (1 << i) - 1;
  
    // Capturing bits from i-1 to 0
    int captured_bits = n & capture_mask;
  
    // Clearing bits from j to 0
    n &= clear_mask;
  
    // Shiftng m to align with n
    m = m << i;
  
    // Insert m into n
    n |= m;
  
    // Insert captured bits
    n |= captured_bits;
  
    return n;
}
  
// Driver Code
static public void Main (String []args) 
{
    // print original bitset
    int N = 1201, M = 8, i = 3, j = 6;
    Console.Write("N = " + N + "(");
    bin(N);
    Console.WriteLine(")");
      
    // print original bitset
    Console.Write("M = " + M + "(");
    bin(M);
    Console.WriteLine(")");
      
    // Call function to 
    // insert M to N
    N = insertion(N, M, i, j);
    Console.WriteLine("After inserting M " + 
                      "into N from 3 to 6");
      
    // Print the inserted bitset
    Console.Write("N = " + N + "(");
    bin(N);
    Console.WriteLine(")");
}
}
  
// This code is contributed
// by Arnab Kundu

PHP

 1)
        bin($n / 2);
    echo $n % 2;
}
  
// Insert m into n
function insertion($n, $m, $i, $j)
{
    $clear_mask = -1 << ($j + 1);
    $capture_mask = (1 << $i) - 1;
  
    // Capturing bits from i-1 to 0
    $captured_bits = $n & $capture_mask;
  
    // Clearing bits from j to 0
    $n &= $clear_mask;
  
    // Shiftng m to align with n
    $m = $m << $i;
  
    // Insert m into n
    $n |= $m;
  
    // Insert captured bits
    $n |= $captured_bits;
  
    return $n;
}
  
// Driver Code
  
// print original bitset
$N = 1201;
$M = 8;
$i = 3;
$j = 6;
echo "N = " . $N ."(";
bin($N);
echo ")" ."\n";
  
// print original bitset
echo "M = " . $M ."(";
bin($M);
echo ")". "\n";
  
// Call function to insert M to N
$N = insertion($N, $M, $i, $j);
echo "After inserting M into N " .
              "from 3 to 6" ."\n";
  
// Print the inserted bitset
echo "N = " . $N . "(";
bin($N);
echo ")". "\n";
  
// This code is contributed 
// by ChitraNayal
?>

输出：

N = 1201(10010110001)
M = 8(1000)
After inserting M into N from 3 to 6
N = 1217(10011000001)