CryptoPlant

// Cấu trúc chứa thông tin các tài khoản cần thiết cho việc tạo người chơi#[derive(Accounts)]pub struct CreatePlayer<'info> {    // Admin thực hiện ký và trả phí tạo tài khoản    #[account(mut)]    pub admin: Signer<'info>,     // Tài khoản lưu thông tin người chơi (PDA)    #[account(        init,        payer = admin, // Admin trả phí        space = 8 + Player::INIT_SPACE,        seeds = [b"player", authority.key().as_ref()],        bump    )]    pub player: Account<'info, Player>,     // Authority lưu public key người chơi (không cần ký)    pub authority: SystemAccount<'info>,     pub system_program: Program<'info, System>,} // Cấu trúc chứa thông tin các tài khoản cần thiết cho việc cập nhật điểm số

1. Line 30 pub admin: Signer<'info>,: Requires this account to have signed the transaction.
2. Line 34 init,: Creates and pays for a new account. Space and payer must be specified.
3. Line 37 seeds = [b"player", authority.key().as_ref()],: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
4. Line 38 bump: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.

        amount_sol,    );    anchor_lang::solana_program::program::invoke(        &transfer_sol_ix,        &[            ctx.accounts.user.to_account_info(),            ctx.accounts.sol_vault.to_account_info(),        ],    )?;     let ctc_amount = amount_sol        .checked_mul(exchange.rate)        .ok_or(ErrorCode::NumberOverflow)?;     let seeds = &[b"exchange", exchange.admin.as_ref(), &[ctx.bumps.exchange]];    let signer = &[&seeds[..]];     let cpi_accounts = Transfer {        from: ctx.accounts.ctc_vault.to_account_info(),        to: ctx.accounts.user_ctc_ata.to_account_info(),        authority: ctx.accounts.exchange.to_account_info(),    };     let cpi_ctx = CpiContext::new_with_signer(

1. Line 15 anchor_lang::solana_program::program::invoke(: Makes a cross-program invocation into another program.
2. Line 24 .checked_mul(exchange.rate): Uses checked arithmetic so overflow fails instead of wrapping.
3. Line 27 let seeds = &[b"exchange", exchange.admin.as_ref(), &[ctx.bumps.exchange]];: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
4. Line 36 let cpi_ctx = CpiContext::new_with_signer(: Makes a CPI signed by a PDA. The signer seeds prove the program controls that address.

    exchange.ctc_mint = ctx.accounts.ctc_mint.key(); // Lưu public key của token mint    exchange.ctc_vault = ctx.accounts.ctc_vault.key(); // Lưu public key của ví CTC    exchange.sol_vault = ctx.accounts.sol_vault.key(); // Lưu public key của ví SOL    exchange.rate = rate;                            // Lưu tỷ giá quy đổi    Ok(())} // Cấu trúc chứa thông tin các tài khoản cần thiết cho việc khởi tạo sàn#[derive(Accounts)]pub struct InitializeExchange<'info> {    // Tài khoản sàn giao dịch (PDA)    #[account(        init,                    // Khởi tạo tài khoản mới        payer = admin,           // Admin trả phí khởi tạo        seeds = [b"exchange", admin.key().as_ref()], // Seeds để tạo PDA        bump,                    // Lưu bump seed        space = 8 + 32 + 8, // Không gian cần thiết cho tài khoản      )]    pub exchange: Account<'info, Exchange>,     // Tài khoản admin (người khởi tạo sàn)    #[account(mut)]    pub admin: Signer<'info>,

1. Line 25 init, // Khởi tạo tài khoản mới: Creates and pays for a new account. Space and payer must be specified.
2. Line 27 seeds = [b"exchange", admin.key().as_ref()], // Seeds để tạo PDA: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
3. Line 28 bump, // Lưu bump seed: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
4. Line 35 pub admin: Signer<'info>,: Requires this account to have signed the transaction.

use anchor_lang::prelude::*;use anchor_spl::token::{self, Burn, Mint, Token, TokenAccount}; use crate::state::Player; #[derive(Accounts)]pub struct UseItem<'info> {    #[account(        mut,        seeds = [b"player", authority.key().as_ref()],        bump,        has_one = authority,    )]    pub player: Account<'info, Player>,     pub authority: Signer<'info>,     pub item_mint: Account<'info, Mint>,     #[account(        mut,        associated_token::mint = item_mint,        associated_token::authority = authority    )]

1. Line 10 seeds = [b"player", authority.key().as_ref()],: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
2. Line 11 bump,: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
3. Line 12 has_one = authority,: Checks that a stored pubkey field matches the passed account.
4. Line 16 pub authority: Signer<'info>,: Requires this account to have signed the transaction.