# 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.

```

## 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.

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

## C++

 `// C++ program for above implementation ` `#include ` `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

 ` `

Output :

```18
```

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