Example C++ Blockchain Code for a Cryptocurrency Such as Bitcoin to function
Here is a skeleton of a C++ program that could be used to implement a cryptocurrency called SAS coin:
#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
// A class to represent a transaction in the SAS coin system
class Transaction {
public:
std::string sender;
std::string receiver;
int amount;
// Constructor
Transaction(std::string sender, std::string receiver, int amount) {
this->sender = sender;
this->receiver = receiver;
this->amount = amount;
}
};
// A class to represent a block in the SAS coin blockchain
class Block {
public:
int index;
std::vector<Transaction> transactions;
std::string previousHash;
std::string hash;
// Constructor
Block(int index, std::vector<Transaction> transactions, std::string previousHash) {
this->index = index;
this->transactions = transactions;
this->previousHash = previousHash;
this->hash = calculateHash();
}
private:
std::string calculateHash() {
// TODO: Implement a function to calculate the hash of a block
// using the SHA-256 hash function and return the result as a string
}
};
// A class to represent the SAS coin blockchain
class Blockchain {
public:
std::vector<Block> chain;
std::unordered_map<std::string, int> balances;
// Constructor
Blockchain() {
// Create the genesis block
std::vector<Transaction> transactions;
Block genesisBlock(0, transactions, "0");
chain.push_back(genesisBlock);
}
void addBlock(std::vector<Transaction> transactions) {
// TODO: Implement a function to add a new block to the blockchain
// with the given transactions and the correct previous hash
}
bool isValid() {
// TODO: Implement a function to check if the blockchain is valid
// by verifying the hashes of each block and the integrity of the transactions
}
};
int main() {
// TODO: Implement the main function to simulate the SAS coin system
// using the Blockchain class and the Transaction and Block classes
return 0;
}
This is just a skeleton of the code, and there are several important functions that need to be implemented in order to complete the program. For example, the calculateHash function in the Block class is responsible for calculating the hash of a block using the SHA-256 hash function. The addBlock function in the Blockchain class is responsible for adding a new block to the blockchain with the given transactions and the correct previous hash. The isValid function in the Blockchain class is responsible for verifying the integrity of the blockchain by checking the hashes of each block and the validity of the transactions.
#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
// A class to represent a transaction in the SAS coin system
class Transaction {
public:
std::string sender;
std::string receiver;
int amount;
// Constructor
Transaction(std::string sender, std::string receiver, int amount) {
this->sender = sender;
this->receiver = receiver;
this->amount = amount;
}
};
// A class to represent a block in the SAS coin blockchain
class Block {
public:
int index;
std::vector<Transaction> transactions;
std::string previousHash;
std::string hash;
// Constructor
Block(int index, std::vector<Transaction> transactions, std::string previousHash) {
this->index = index;
this->transactions = transactions;
this->previousHash = previousHash;
this->hash = calculateHash();
}
private:
std::string calculateHash() {
// Use the SHA-256 hash function to calculate the hash of a block
// based on its index, transactions, and previous hash
// and return the result as a string
// TODO: Implement this function
}
};
// A class to represent the SAS coin blockchain
class Blockchain {
public:
std::vector<Block> chain;
std::unordered_map<std::string, int> balances;
// Constructor
Blockchain() {
// Create the genesis block
std::vector<Transaction> transactions;
Block genesisBlock(0, transactions, "0");
chain.push_back(genesisBlock);
}
void addBlock(std::vector<Transaction> transactions) {
// Add a new block to the blockchain with the given transactions
// and the correct previous hash
// TODO: Implement this function
}
bool isValid() {
// Check if the blockchain is valid by verifying the hashes of each block
// and the integrity of the transactions
// TODO: Implement this function
}
};
int main() {
// Create a new instance of the Blockchain class
Blockchain blockchain;
// Create some transactions and add them to the blockchain
std::vector<Transaction> transactions;
transactions.push_back(Transaction("Alice", "Bob", 10));
transactions.push_back(Transaction("Charlie", "Dave", 5));
blockchain.addBlock(transactions);
transactions.clear();
transactions.push_back(Transaction("Bob", "Alice", 3));
transactions.push_back(Transaction("Dave", "Charlie", 2));
blockchain.addBlock(transactions);
// Print the contents of the blockchain
for (const auto& block : blockchain.chain) {
std::cout << "Block #" << block.index << std::endl;
std::cout << "Previous Hash: " << block.previousHash << std::endl;
std::cout << "Hash: " << block.hash << std::endl;
std::c
#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
// A class to represent a transaction in the SAS coin system
class Transaction {
public:
std::string sender;
std::string receiver;
int amount;
// Constructor
Transaction(std::string sender, std::string receiver, int amount) {