Merge Project

A small TypeScript project that implements a merge function for three integer collections and includes unit tests using Jest.

Requirements

• Node.js (v18 or later recommended)
• npm

Setup

Install project dependencies:

npm install

Run

Execute the sample program:

npm run start

Run Unit Tests

Execute all unit tests:

npm test

Project Structure

merge-project/
├── src/
│   └── index.ts           # Merge implementation
├── tests/
│   └── merge.test.ts      # Unit tests
├── jest.config.js         # Jest + ts-jest configuration
├── package.json           # Scripts and dependencies
├── tsconfig.json          # TypeScript configuration
└── README.md              # Project documentation

Algorithm

The solution takes advantage of the input constraints:

• collection1 is sorted in ascending order.
• collection2 is sorted in descending order.
• collection3 is sorted in ascending order.

Instead of sorting all values again, the implementation:

1. Merges collection1 with collection2 by traversing collection2 from the end.
2. Merges the intermediate result with collection3.

No built-in sorting function (such as Array.prototype.sort) is used.

Complexity

• Time Complexity: O(n1 + n2 + n3)
• Space Complexity: O(n1 + n2 + n3)