hybrid consensus

Question

I try to implement the hybrid consensus from the substrate recipes book but it keeps failing. I tried to use the sha3 algorithm for PoW but I keep getting this error:

"the trait PowAlgorithm<_> is not implemented for `MinimalSha3Algorithm"

This is my code in rust:

 #[derive(Clone)]
    pub struct MinimalSha3Algorithm;
    
    // Here we implement the general PowAlgorithm trait for our concrete Sha3Algorithm
    impl<B: BlockT<Hash = H256>> PowAlgorithm<B> for MinimalSha3Algorithm {
        type Difficulty = U256;
    
        fn difficulty(&self, _parent: B::Hash) -> Result<Self::Difficulty, Error<B>> {
            // Fixed difficulty hardcoded here
            Ok(U256::from(1_000_000))
        }
    
        fn verify(
            &self,
            _parent: &BlockId<B>,
            pre_hash: &H256,
            _pre_digest: Option<&[u8]>,
            seal: &RawSeal,
            difficulty: Self::Difficulty,
        ) -> Result<bool, Error<B>> {
            // Try to construct a seal object by decoding the raw seal given
            let seal = match Seal::decode(&mut &seal[..]) {
                Ok(seal) => seal,
                Err(_) => return Ok(false),
            };
    
            // See whether the hash meets the difficulty requirement. If not, fail fast.
            if !hash_meets_difficulty(&seal.work, difficulty) {
                return Ok(false);
            }
    
            // Make sure the provided work actually comes from the correct pre_hash
            let compute = Compute {
                difficulty,
                pre_hash: *pre_hash,
                nonce: seal.nonce,
            };
    
            if compute.compute() != seal {
                return Ok(false);
            }
    
            Ok(true)
        } 
        
    }

I'd appreciate any help!