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

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 modified in 4th step).
7. The result will be N with M as substring from ith to jth bits

Output :

18

Time Complexity: O(1)

Auxiliary Space: O(1)