Anchor counter increment

lib.rs

use anchor_lang::prelude::*;

// This is your program's public key and it will update
// automatically when you build the project.
declare_id!("HAcYnZCEXGs31qKPXEJUEjPDBnxSLLL2CxSqp4zrpHze");

#[program]
mod plus_one {
    use super::*;
    pub fn initialize(ctx: Context<Initialize>) -> Result<()> {
        ctx.accounts.counter.bump = *ctx.bumps.get("counter").unwrap();
        ctx.accounts.counter.count = 0u64;
        Ok(())
    }

    pub fn increment(ctx: Context<Increment>) -> Result<()> {
        ctx.accounts.counter.count = ctx.accounts.counter.count + 1;
        Ok(())
    }
}

#[derive(Accounts)]
pub struct Initialize<'info> {
    #[account(mut)]
    pub owner: Signer<'info>,
    #[account(init, seeds = [b"counter", owner.key().as_ref()], payer = owner, bump, space = 8 + 8 + 1)]
    pub counter: Account<'info, Counter>,
    pub system_program: Program<'info, System>,
}

#[derive(Accounts)]
pub struct Increment<'info> {
    #[account(mut)]
    pub owner: Signer<'info>,
    #[account(mut, seeds = [b"counter", owner.key().as_ref()], bump = counter.bump)]
    pub counter: Account<'info, Counter>,
    pub system_program: Program<'info, System>,
}

// let counter_seed = [b"counter", signer.key().as_ref()];
// let (counter_pda, counter_bump) = Pubkey::find_program_address(&counter_seed, &Program::id());

#[account]
pub struct Counter {
    count: u64,
    bump: u8
}