const crypto = require('crypto');



function mineBlock(previousHash, data, difficulty) {

 let nonce = 0;

 let hash = '';

 const target = '0'.repeat(difficulty);



 while (!hash.startsWith(target)) {

 nonce++;

 hash = crypto.createHash('sha256')

 .update(previousHash + data + nonce)

 .digest('hex');

 }

 return { nonce, hash };

}



// Example

const result = mineBlock('0000abc...', 'Rahul transaction', 4);

console.log(result);

# very basic example using hashlib (not real mining)

import hashlib

import time



def mine(data, difficulty):

 nonce = 0

 while True:

 text = f"{data}{nonce}"

 hash_result = hashlib.sha256(text.encode()).hexdigest()

 if hash_result.startswith('0' * difficulty):

 return nonce, hash_result

 nonce += 1



start = time.time()

nonce, hash_val = mine("test block", 5)

print(f"Found: {nonce} | Hash: {hash_val}")

print(f"Time taken: {time.time() - start:.2f}s")