Insert a Pattern of Ones Into a 32-bit Integer

Question

## Problem

Given a 32-bit integer, set (insert) a pattern of ones between bit positions `i` and `j` using masks — no loops where avoidable.

## Example
```
n=0b1000, set bits [1..2] -> 0b1110
```

## Constraints
- 0 ≤ i ≤ j ≤ 31

## Approach
Build a mask `((1<<(j-i+1))-1) << i` and OR it in. A reported Qualcomm bit-manipulation question.