Ending game automatically when statis is reached

plus properly seeding math/rand and swapping the chars used for grid to
better match black/white from canonical example.

conway/go/conways-game-of-life/main.go

@@ -29,15 +29,27 @@ func main() {
 		os.Exit(2)
 	}
 
+	cksum := game.Checksum()
+
 	ticks := time.Tick(time.Duration(*sleepMs) * time.Millisecond)
 	generations := 0
 	for now := range ticks {
 		fmt.Printf("\nGeneration %v\n%v\n", generations, now)
 		fmt.Println(game)
+
 		game.EvaluateGeneration()
+
+		if cksum == game.Checksum() {
+			fmt.Println("Stasis!")
+			os.Exit(0)
+		}
+
+		cksum = game.Checksum()
+
 		if *mutate && generations%2 == 0 {
 			game.Mutate()
 		}
+
 		generations++
 	}
 }

conway/go/game_of_life.go

@@ -7,8 +7,13 @@ import (
 	"math"
 	"math/rand"
 	"strings"
+	"time"
 )
 
+func init() {
+	rand.Seed(time.Now().UTC().UnixNano())
+}
+
 type GameOfLife struct {
 	State *GameState
 }
@@ -159,6 +164,10 @@ func (state *GameState) Mutate() error {
 	return nil
 }
 
+func (game *GameOfLife) Checksum() string {
+	return game.State.Checksum()
+}
+
 func (state *GameState) Checksum() string {
 	ck := sha1.New()
 	cells := make(chan *GameStateCell)
@@ -282,7 +291,7 @@ func (state *GameState) String() string {
 				return ""
 			}
 
-			if value == 0 {
+			if value == 1 {
 				stringVal = "·"
 			}
 			cells = append(cells, stringVal)