Set bits in N equals to M in the given range.

You are given two 32-bit numbers, N and M, and two bit positions, i and j. Write a method to set all bits between i and j in N equal to M (e.g., M becomes a substring of N located at i and starting at j).

Examples :

Input : N = 1, M = 2, i = 2, j = 4
Output: 9
N = 00000001(Considering 8 bits only)
M = 10 (Binary of 2) For more indexes,
leading zeroes will be considered.
Now set 3 bits from ith index to j in 
the N as in the M.
Bits:-    0 0 0 (0  1  0) 0 1 = 9
Indexes:- 7 6 5  4  3  2  1 0
From index 2 to 4, bits are set according 
to the M.

Asked in : Adobe

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

A simple solution is to traverse all bits in N from 0 to 31 and set the bits equals to M in the range from i to j.

An efficient solution is to do following steps.

Set all the bits after j in a number.
Set all the bits before i in a number.
Then perform Bitwise Or on both then we get the number with all the bits set except from i to j.
Perform Bitwise And with the given N as to set the bits according to the N.
Then shift M into the correct position i.e. in the range of i to j.
And at the last perform Bitwise Or on (Shifted M and the N modifed in 4th step).
The result will be N with M as substring from ith to jth bits

C++

// C++ program for above implementation 
#include <iostream> 
using namespace std; 
  
// Function to set the bits 
int setBits(int n, int m, int i, int j) 
{ 
    // number with all 1's 
    int allOnes = ~0; 
  
    // Set all the bits in the left of j 
    int left = allOnes << (j + 1); 
  
    // Set all the bits in the right of j 
    int right = ((1 << i) - 1); 
  
    // Do Bitwsie OR to get all the bits  
    // set except in the range from i to j 
    int mask = left | right; 
  
    // clear bits j through i 
    int masked_n = n & mask; 
  
    // move m into the correct position 
    int m_shifted = m << i; 
  
    // return the Bitwise OR of masked_n  
    // and shifted_m 
    return (masked_n | m_shifted); 
} 
  
// Drivers program 
int main() 
{ 
    int n = 2, m = 4; 
    int i = 2, j = 4; 
    cout << setBits(n, m, i, j); 
    return 0; 
} 

Java

// Java Program  
public class GFG 
{ 
    // Function to set the bits 
    static int setBits(int n, int m, int  i, int j) 
    { 
          
        // number with all 1's 
        int  allOnes = ~0; 
          
        // Set all the bits in the left of j 
        int left = allOnes << (j + 1); 
          
        // Set all the bits in the right of j 
        int right = ((1 << i) - 1); 
          
        // Do Bitwise OR to get all the bits  
        // set except in the range from i to j 
        int mask = left | right; 
          
        // clear bits j through i 
        int masked_n = n & mask; 
          
        // move m into the correct position 
        int m_shifted = m << i; 
          
        // return the Bitwise OR of masked_n  
        // and shifted_m 
        return (masked_n | m_shifted); 
    } 
      
    // Driver Program to test above function 
    public static void main(String[] args)  
    { 
        int n = 2, m = 4; 
        int i = 2, j = 4; 
        System.out.println(setBits(n, m, i, j)); 
    } 
} 
// This code is contributed by Sumit Ghosh 

Python

# Python program for above implementation 
  
# Function to set the bits 
def setBits(n, m, i, j): 
  
    # number with all 1's 
    allOnes = not 0
   
    # Set all the bits in the left of j 
    left = allOnes << (j + 1) 
   
    # Set all the bits in the right of j 
    right = ((1 << i) - 1) 
   
    # Do Bitwsie OR to get all the bits  
    # set except in the range from i to j 
    mask = left | right 
   
    # clear bits j through i 
    masked_n = n & mask 
   
    # move m into the correct position 
    m_shifted = m << i 
   
    # return the Bitwise OR of masked_n  
    # and shifted_m 
    return (masked_n | m_shifted) 
   
# Drivers program 
n, m = 2, 4
i, j = 2, 4
print setBits(n, m, i, j) 
  
# This code is submitted by Sachin Bisht 

C#

// C# Program for above implementation 
using System; 
  
public class GFG { 
      
    // Function to set the bits 
    static int setBits(int n, int m, int  i, int j) 
    { 
           
        // number with all 1's 
        int  allOnes = ~0; 
           
        // Set all the bits in the left of j 
        int left = allOnes << (j + 1); 
           
        // Set all the bits in the right of j 
        int right = ((1 << i) - 1); 
           
        // Do Bitwise OR to get all the bits  
        // set except in the range from i to j 
        int mask = left | right; 
           
        // clear bits j through i 
        int masked_n = n & mask; 
           
        // move m into the correct position 
        int m_shifted = m << i; 
           
        // return the Bitwise OR of masked_n  
        // and shifted_m 
        return (masked_n | m_shifted); 
    } 
       
    // Driver Program to test above function 
    public static void Main()  
    { 
        int n = 2, m = 4; 
        int i = 2, j = 4; 
          
        Console.WriteLine(setBits(n, m, i, j)); 
    } 
} 
  
// This code is contributed by Anant Agarwal. 

PHP

<?php 
// PHP program for above implementation 
  
// Function to set the bits 
function setBits($n, $m, $i, $j) 
{ 
    // number with all 1's 
    $allOnes = ~0; 
  
    // Set all the bits  
    // in the left of j 
    $left = $allOnes << ($j + 1); 
  
    // Set all the bits  
    // in the right of j 
    $right = ((1 << $i) - 1); 
  
    // Do Bitwsie OR to get all  
    // the bits set except in  
    // the range from i to j 
    $mask = $left | $right; 
  
    // clear bits j through i 
    $masked_n = $n & $mask; 
  
    // move m into the  
    // correct position 
    $m_shifted = $m << $i; 
  
    // return the Bitwise OR  
    // of masked_n and shifted_m 
    return ($masked_n | $m_shifted); 
} 
  
// Driver Code 
$n = 2; $m = 4; 
$i = 2; $j = 4; 
echo setBits($n, $m, $i, $j); 
  
// This code is contributed by ajit 
?> 

Output :

Reference:
https://www.careercup.com/question?id=8863294

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My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

C++

Java

Python

C#

PHP

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