Interview Assignment for Backend/Blockchain Engineer

Objective:

Design and implement an API that allows users to store key-value pairs in a smart contract and retrieve values by providing the corresponding keys.

Write a smart contract in Solidity that can store key-value pairs and retrieve values using keys. The smart contract should have functions for setting key-value pairs and getting values by keys. Both key and values are integers.
Set up a project to interact with the smart contract. Include necessary dependencies and configurations in the project.
Deploys the smart contract to a local Ethereum test network (e.g., Ganache, Hardhat, Anvil).
Use the ABI and contract address to create an instance of the smart contract.
Design and implement the API with the following endpoints:

POST /store: Stores a key-value pair in the smart contract. Request Body: { "key": "<key>", "value": "<value>" } Response: { "success": true, "message": "Key-value pair stored successfully." }
GET /retrieve?key=<key>: Retrieves the value corresponding to the provided key from the smart contract. Response: { "key": "<key>", "value": "<value>" }