func (bc *blockchain) proofOfWork(lastProof int) (proof int) {
	for {
		if validProof(lastProof, proof) {
			return
		}
		proof++
	}
}
// Simple Proof of Work Algorithm:
// - Find a number p' such that hash(pp') contains leading 4 zeroes,
// - p is the previous proof, and p' is the new proof
Simple Proof of Work Algorithm:
- Find a number p' such that hash(pp') contains leading 4 zeroes,
- p is the previous proof, and p' is the new proof
// Simple Proof of Work Algorithm : // - Find a number p ' such that hash ( pp ' ) contains leading 4 zeroes // - p is the previous proof and p ' is the new proof
func (bc *blockchain) proofOfWork(lastProof int) (proof int) {
	for {
		if validProof(lastProof, proof) {
			return
		}
		proof++
	}
}
func ( bc * blockchain ) proofOfWork ( lastProof int ) ( proof int ) { for { if validProof ( lastProof , proof ) { return } proof ++ } }
Simple Proof of Work Algorithm:
 Find a number p' such that hash(pp') contains leading 4 zeroes,
 p is the previous proof, and p' is the new proof
Simple Proof of Work Algorithm : Find a number p ' such that hash ( pp ' ) contains leading 4 zeroes p is the previous proof and p ' is the new proof