Playing with rolls of dice or whatebbs

algs4/src/meatballhat.com/algs4-rolls/main.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+)
+
+import (
+	"meatballhat.com/algs4"
+)
+
+const (
+	USAGE string = "Usage: algs4-rolls <nrolls>"
+	SIDES        = 6
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Println(USAGE)
+		os.Exit(1)
+	}
+
+	nrolls, err := strconv.ParseInt(os.Args[1], 10, 32)
+	if err != nil {
+		fmt.Println("Wat.", err)
+		os.Exit(2)
+	}
+
+	rolls, err := algs4.Rolls(nrolls)
+
+	for i := 1; i <= algs4.ROLL_SIDES; i += 1 {
+		fmt.Println(rolls[i])
+	}
+}

algs4/src/meatballhat.com/algs4/rolls.go

@@ -0,0 +1,33 @@
+package algs4
+
+import (
+	"crypto/rand"
+	"fmt"
+	"math/big"
+)
+
+const ROLL_SIDES = 6
+
+func Rolls(nrolls int64) ([]*Counter, error) {
+	var err error
+
+	rolls := make([]*Counter, ROLL_SIDES+1)
+	for i := 1; i <= ROLL_SIDES; i += 1 {
+		rolls[i] = NewCounter(fmt.Sprintf("%d's", i))
+	}
+
+	var result *big.Int
+	randMax := big.NewInt(ROLL_SIDES)
+
+	for t := int64(0); t < nrolls; t += 1 {
+		result, err = rand.Int(rand.Reader, randMax)
+
+		if err != nil {
+			return nil, err
+		}
+
+		rolls[int(result.Int64())+1].Increment()
+	}
+
+	return rolls, nil
+}