A smart contract that enables a raffle/lottery on the Neo block chain. Surprisingly tricky.
Send GAS, win GAS!
The contract on TestNet is: AGbcQUTrFbK7xSJeUZgFHLVAxXE9R3RiKf
Here's an example round:
Ticket #1: e09083d2ac634092d2fc31ca56f8750fbd70749ba7944358f1054e3a040ebb6f 2.5 GAS
Ticker #2: 03dfeb213d99593a3c9666520c9e28cc24133224c969e7bb03504b0a248e93a6 3 GAS
Ticket #3: 4f918745534f3aac4af071fa0957028cfa53d3ca2cc3a85af5982ee0d7372007 1 GAS
The drawing happens in two steps, first a sweep transaction sweeps all the tickets into one transaction that gets sent back the contract address. This TXID is used as a parameter to invoke the contract's "drawing" operation, where the winner is picked from the sweep's inputs and saved in storage.