pda_example.rs

use anchor_lang::prelude::*;

declare_id!("GofNwzpGJNLTk5m2ME9iYbdT2X9ofuzrDPmio8Kg6oG1");

#[program]
pub mod crunchy_vs_smooth {
    use super::*;

    pub fn initialize(ctx: Context<Initialize>, vote_account_bump: u8) -> ProgramResult {
        ctx.accounts.voteting_state.bump = vote_account_bump;
        Ok(())
    }

    pub fn vote_crunchy(ctx: Context<Vote>) -> ProgramResult {
        ctx.accounts.voteing_state.crunchy += 1;
        Ok(())
    }

    pub fn vote_smooth(ctx: Context<Vote>) -> ProgramResult {
        ctx.accounts.voteing_state.smooth += 1;
        Ok(())
    }
}

#[derive(Accounts)]
#[instruction(vote_account_bump: u8)]
pub struct Initialize<'info> {
    #[account(init, payer = voter, seeds = [b"vote_state".as_ref()], bump = vote_account_bump)]
    pub voteting_state: Account<'info, VotingState>,
    #[account(mut)]
    pub voter: Signer<'info>,
    pub system_program: Program<'info, System>
}

#[account]
#[derive(Default)]
pub struct VotingState {
    pub crunchy: u64,
    pub smooth: u64,
    pub bump: u8
}

#[derive(Accounts)]
pub struct Vote<'info> {
    #[account(mut, seeds = [b"vote_state".as_ref()], bump = voteing_state.bump )]
    pub voteing_state: Account<'info, VotingState>
}

Program Derived Address for Solana Account Example