CONTRACT: Prize Pool Contract

[PoulavBhowmick03]

Title: Automated Prize Distribution Logic
Description
Create contract to manage contest entry fees and prize distributions.

Acceptance Criteria:

• Tracks locked funds per contest
• Distributes prizes to top 3 positions:
  • 1st: 50%
  • 2nd: 30%
  • 3rd: 20%
• Allows withdrawals after contest conclusion
• Prevents double entry with participant mapping

Technical Details:

#[starknet::contract]
mod PrizePool {
    #[storage]
    struct Storage {
        balances: LegacyMap<(felt252, felt252), u64>, // (contest_id, user)
        prize_distribution: LegacyMap<felt252, (u64, u64, u64)>
    }

    #[external(v0)]
    fn lock_funds(ref self: ContractState, contest_id: felt252, amount: u64) {
        let user = get_caller_address();
        assert(amount > 0, 'Invalid amount');
        
        let current = self.balances.read((contest_id, user));
        self.balances.write((contest_id, user), current + amount);
    }

    #[external(v0)]
    fn distribute_prizes(
        ref self: ContractState, 
        contest_id: felt252,
        ranks: Array<felt252> // [1st, 2nd, 3rd]
    ) {
        assert(ranks.len() == 3, 'Invalid ranks');
        let total = self.total_prize_pool.read(contest_id);
        
        let amounts = (
            total * 50 / 100, // 50%
            total * 30 / 100, // 30%
            total * 20 / 100  // 20%
        );

        // Transfer logic
        self._transfer(ranks[0], amounts.0);
        self._transfer(ranks[1], amounts.1);
        self._transfer(ranks[2], amounts.2);
        
        self.prize_distribution.write(contest_id, amounts);
    }
}

Notes:

• Add emergency withdrawal safety
• Implement decimal precision handling
• Add contest duration checks

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