refactor

main.go

@@ -3,19 +3,20 @@ package main
 import (
 	"crypto"
 	_ "crypto/sha1"
-	"encoding/hex"
+	"encoding/base64"
 	"fmt"
 	"math/rand"
+	"os"
 	"time"
 )
 
 func main() {
 	g := Generator{
-		Difficulty: 26,
+		Difficulty: 25,
 	}
 	c := g.RandomChallenge()
+	c.Solve()
 	fmt.Println(c.String())
-	fmt.Println(c.Solve().String())
 }
 
 type Challenge struct {
@@ -23,6 +24,7 @@ type Challenge struct {
 	Date       [20]byte
 	Difficulty byte
 	Solution   int64
+	bytes      []byte
 }
 type Generator struct {
 	Difficulty byte
@@ -63,38 +65,45 @@ var prefixLookup = []int{
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 }
 
-func (c Challenge) Solve() Challenge {
+func (c *Challenge) Solve() {
-	bytes := make([]byte, 76)
+	c.bytes = make([]byte, 76)
-	bytes = append(bytes, c.Input[:]...)
+	c.bytes = append(c.bytes, c.Input[:]...)
-	bytes = append(bytes, c.Date[:]...)
+	c.bytes = append(c.bytes, c.Date[:]...)
+	timer := time.Now()
 	for {
-		for i := range 8 {
+		s := c.Validate()
-			bytes[75-i] = byte(c.Solution >> (i * 8))
+		if s {
-		}
+			fmt.Fprintf(os.Stderr, "%s: found solution %d in %dms\n", c.String(), c.Solution, time.Since(timer).Milliseconds())
-		sum := make([]byte, 20)
-		hash := crypto.SHA1.New()
-		hash.Write(bytes)
-		sum = hash.Sum(nil)
-		count := 0
-		for _, c := range sum {
-			p := prefixLookup[c]
-			count += p
-			if p != 8 {
-				break
-			}
-		}
-		if c.Solution%20000000 == 0 {
-			println(c.Solution)
-		}
-		if count >= int(c.Difficulty) {
-			println(c.Solution)
 			break
 		}
+		if c.Solution > 0xffffffffffffff {
+			fmt.Fprintf(os.Stderr, "%s: could not find solution!", c.String())
+		}
 		c.Solution++
 	}
-	return c
 }
-func (c Challenge) String() string {
+func (c *Challenge) CheckValue(v int64) bool {
+	for i := range 8 {
+		c.bytes[75-i] = byte(v >> (i * 8))
+	}
+	sum := make([]byte, 20)
+	hash := crypto.SHA1.New()
+	hash.Write(c.bytes)
+	sum = hash.Sum(nil)
+	count := 0
+	for _, c := range sum {
+		p := prefixLookup[c]
+		count += p
+		if p != 8 {
+			break
+		}
+	}
+	return count >= int(c.Difficulty)
+}
+func (c *Challenge) Validate() bool {
+	return c.CheckValue(c.Solution)
+}
+func (c *Challenge) String() string {
 	bytes := make([]byte, 0)
 	bytes = append(bytes, c.Input[:]...)
 	bytes = append(bytes, c.Date[:]...)
@@ -103,5 +112,5 @@ func (c Challenge) String() string {
 	for i := range 7 {
 		bytes[75-i] = byte(c.Solution >> (i * 8))
 	}
-	return hex.EncodeToString(bytes)
+	return base64.URLEncoding.EncodeToString(bytes)
 }