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).

EXAMPLE:
Input: N = 10000000000, M = 10101, i = 2, j = 6
Output: N = 10001010100

This code operates by clearing all bits in N between position i and j, and then ORing to put
M in there.
1       public static int updateBits(int n, int m, int i, int j) {
2               int max = ~0; /* All 1’s */
3          
4               // 1’s through position j, then 0’s
5               int left = max - ((1 << j) - 1);
6   
7               // 1’s after position i
8              int right = ((1 << i) - 1);
9   
10              // 1’s, with 0s between i and j
11              int mask = left | right;
12   
13              // Clear i through j, then put m in there
14              return (n & mask) | (m << i);
15      }