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Secure Token Transfer in Solidity
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Secure Token Transfer in Solidity

EasyPython

Problem

Write a Solidity smart contract that implements a simple token transfer with basic security checks.

Implement the transfer logic represented by the reference function below. Reject nonpositive amounts, the zero address, unknown senders, and transfers exceeding the sender's balance. Failed transfers must leave balances unchanged.

Input: balances, sender, recipient, and integer amount. Output: an object containing success and the resulting balances.

Constraints

  • balances is a mapping from address strings to nonnegative integer balances
  • sender and recipient are address strings
  • amount is an integer
  • The zero address is represented by "0x0"
  • A failed transfer must not modify balances

Function Signature

def transfer_token(balances, sender, recipient, amount):
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