Arbitron

    msg!("Winner amount: {}", winner_amount);     let host_key = contest.host.key();    let contest_bump = [contest.bump];    let contest_name_bytes = contest.name.as_bytes();    let contest_seeds = &[        b"contest".as_ref(),        contest_name_bytes,         host_key.as_ref(),        &contest_bump,     ][..];     let signer_seeds = &[contest_seeds][..];      if winner_amount > 0 {        let winner_transfer_accounts = TransferChecked {            from: prize_pool_vault.to_account_info(),            mint: ctx.accounts.token_mint.to_account_info(),            to: ctx.accounts.winner_usdc_account.to_account_info(),            authority: contest.to_account_info(),         };        let cpi_ctx_winner = CpiContext::new_with_signer(            ctx.accounts.token_program.to_account_info(),            winner_transfer_accounts,            signer_seeds, 

1. Line 85 msg!("Winner amount: {}", winner_amount);: Logs to the program log, which is visible in explorers and the test output.
2. Line 88 let contest_bump = [contest.bump];: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
3. Line 90 let contest_seeds = &[: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
4. Line 99 let winner_transfer_accounts = TransferChecked {: A checked token transfer, which also verifies the mint and decimals.
5. Line 105 let cpi_ctx_winner = CpiContext::new_with_signer(: Makes a CPI signed by a PDA. The signer seeds prove the program controls that address.

        mut,        seeds = [            b"contest",            contest.name.as_bytes(),            contest.host.key().as_ref()        ],        bump = contest.bump,        // constraint = contest.host == host.key() @ErrorCode::UnauthorizedHost,        constraint = contest.status == ContestState::Upcoming @ErrorCode::InvalidContestState,    )]    pub contest: Account<'info, Contest>,} pub fn start_contest(ctx:Context<StartContest>)->Result<()>{     let contest = &mut ctx.accounts.contest;     let clock = Clock::get()?;     require!(contest.participents_count > 1, ErrorCode::MinContestParticipantsError);    require!(clock.unix_timestamp >= contest.start_time, ErrorCode::ContestNotStartedYet);     contest.status = ContestState::Ongoing;    // Contest started and we have recorded the actual start time.

1. Line 14 seeds = [: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
2. Line 19 bump = contest.bump,: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
3. Line 30 let clock = Clock::get()?;: Reads on-chain time from the Clock sysvar.
4. Line 32 require!(contest.participents_count > 1, ErrorCode::MinContestParticipantsError);: An explicit validation that aborts the instruction with an error.

use anchor_lang::prelude::*;use crate::{    Contest, ContestInput,    error::ErrorCode}; #[derive(Accounts)]pub struct StoreContestInput<'info>{    #[account(mut)]    pub payer: Signer<'info>,     pub contest: Account<'info,Contest>,     #[account(        init,        payer = payer,        space = ContestInput::SPACE,        seeds = [            b"contest_inputs",            contest.key().as_ref()        ],        bump    )]    pub contest_inputs : Account<'info,ContestInput>,

1. Line 10 pub payer: Signer<'info>,: Requires this account to have signed the transaction.
2. Line 15 init,: Creates and pays for a new account. Space and payer must be specified.
3. Line 18 seeds = [: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
4. Line 22 bump: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.

use anchor_lang::prelude::*;use crate::config::Config; #[derive(Accounts)]pub struct Initialize<'info>{    #[account(mut)]    pub admin:Signer<'info>,     #[account(        init,        payer = admin,        seeds = [            b"config",        ],        bump,        space = Config::DISCRIMINATOR.len() + Config::INIT_SPACE,    )]    pub config:Account<'info,Config>,     pub system_program:Program<'info,System>,} pub fn initialize(context:Context<Initialize>,platform_fee_wallet:Pubkey,platform_fee_bps:u16, platform_fee_wallet_mint: Pubkey)->Result<()>{

1. Line 7 pub admin:Signer<'info>,: Requires this account to have signed the transaction.
2. Line 10 init,: Creates and pays for a new account. Space and payer must be specified.
3. Line 12 seeds = [: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
4. Line 15 bump,: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.