add dices implementation

The type Dices represent the dice set. It also implements the
game logic checks. (IsFullHouse, ...)

2 files changed, 207 insertions, 0 deletions

diff --git a/goffel/dices.go b/goffel/dices.go
new file mode 100644
index 0000000..113ccb0
--- /dev/null
+++ b/goffel/dices.go
@@ -0,0 +1,95 @@
+package goffel
+
+import (
+	"fmt"
+	"math/rand"
+	"sort"
+)
+
+var diceRunes = [7]string{"", "\u2680", "\u2681", "\u2682", "\u2683", "\u2684", "\u2685"}
+
+type Dices [5]int
+
+func (d *Dices) Roll(i []int) {
+	for _, v := range i {
+		d[v-1] = rand.Int()%6 + 1
+	}
+	sort.Ints(d[0:])
+}
+
+func (d Dices) String() string {
+	s := ""
+	for _, v := range d {
+		s += diceRunes[v] + " "
+	}
+	return fmt.Sprintf("%s", s)
+}
+
+func (d Dices) Sum(i int) int {
+	s := 0
+	for _, v := range d {
+		if v == i || i == 0 {
+			s += v
+		}
+	}
+	return s
+}
+
+func (d Dices) sumSame() []int {
+	s := []int{1}
+	idx := 0
+	for i := 1; i < 5; i++ {
+		if d[i] == d[i-1] {
+			s[idx]++
+		} else {
+			s = append(s, 1)
+			idx++
+		}
+	}
+	sort.Sort(sort.Reverse(sort.IntSlice(s)))
+	return s
+}
+
+func (d Dices) IsThreeOfAKind() bool {
+	return d.sumSame()[0] >= 3
+}
+
+func (d Dices) IsFourOfAKind() bool {
+	return d.sumSame()[0] >= 4
+}
+
+func (d Dices) IsFullHouse() bool {
+	s := d.sumSame()
+	return s[0] == 3 && s[1] == 2
+}
+
+func (d Dices) IsYahtzee() bool {
+	return d.sumSame()[0] >= 5
+}
+
+func (d Dices) isStraight(length int) bool {
+	s := 1
+	max_s := s
+	for i := 0; i < 4; i++ {
+		if d[i]+1 == d[i+1] {
+			s++
+		} else if d[i] != d[i+1] {
+			if s > max_s {
+				max_s = s
+			}
+			s = 1
+		}
+	}
+	if s > max_s {
+		max_s = s
+	}
+	return max_s >= length
+}
+
+func (d Dices) IsSmallStraight() bool {
+	return d.isStraight(4)
+}
+
+func (d Dices) IsLargeStraight() bool {
+	return d.isStraight(5)
+}
diff --git a/goffel/dices_test.go b/goffel/dices_test.go
new file mode 100644
index 0000000..4593fac
--- /dev/null
+++ b/goffel/dices_test.go
@@ -0,0 +1,112 @@
+package goffel
+
+import "testing"
+
+func TestSum(t *testing.T) {
+	d := Dices{1, 1, 1, 2, 6}
+	if d.Sum(1) != 3 {
+		t.Errorf("Sum(1) of %v should be 3", d)
+	}
+	d = Dices{1, 1, 1, 2, 6}
+	if d.Sum(2) != 2 {
+		t.Errorf("Sum(2) of %v should be 2", d)
+	}
+	d = Dices{1, 1, 1, 2, 6}
+	if d.Sum(0) != 11 {
+		t.Errorf("Sum(0) of %v should be 11", d)
+	}
+	d = Dices{1, 1, 1, 2, 6}
+	if d.Sum(3) != 0 {
+		t.Errorf("Sum(3) of %v should be 0", d)
+	}
+}
+
+func TestIsThreeOfAKind(t *testing.T) {
+	dices := []Dices{Dices{1, 2, 3, 3, 3}, Dices{1, 4, 4, 4, 5}, Dices{2, 2, 2, 3, 6}, Dices{1, 1, 1, 1, 1}}
+	for _, d := range dices {
+		if !d.IsThreeOfAKind() {
+			t.Errorf("%v is three of a kind", d)
+		}
+	}
+	dices = []Dices{Dices{1, 2, 3, 3, 4}, Dices{1, 4, 4, 5, 5}, Dices{1, 2, 2, 3, 6}, Dices{1, 1, 2, 5, 6}}
+	for _, d := range dices {
+		if d.IsThreeOfAKind() {
+			t.Errorf("%v is not three of a kind", d)
+		}
+	}
+}
+
+func TestIsFourOfAKind(t *testing.T) {
+	dices := []Dices{Dices{1, 3, 3, 3, 3}, Dices{1, 4, 4, 4, 4}, Dices{2, 2, 2, 2, 6}, Dices{1, 1, 1, 1, 1}}
+	for _, d := range dices {
+		if !d.IsFourOfAKind() {
+			t.Errorf("%v is four of a kind", d)
+		}
+	}
+	dices = []Dices{Dices{1, 2, 3, 3, 4}, Dices{1, 4, 4, 5, 5}, Dices{1, 2, 2, 3, 6}, Dices{1, 1, 2, 5, 6}}
+	for _, d := range dices {
+		if d.IsFourOfAKind() {
+			t.Errorf("%v is not four of a kind", d)
+		}
+	}
+}
+
+func TestIsFullHouse(t *testing.T) {
+	dices := []Dices{Dices{1, 1, 3, 3, 3}, Dices{1, 1, 4, 4, 4}, Dices{2, 2, 2, 6, 6}}
+	for _, d := range dices {
+		if !d.IsFullHouse() {
+			t.Errorf("%v is a full house", d)
+		}
+	}
+	dices = []Dices{Dices{1, 2, 3, 3, 4}, Dices{1, 4, 4, 5, 5}, Dices{1, 2, 2, 3, 6}, Dices{1, 1, 2, 5, 6}}
+	for _, d := range dices {
+		if d.IsFullHouse() {
+			t.Errorf("%v is not a full house", d)
+		}
+	}
+}
+
+func TestIsSmallStraight(t *testing.T) {
+	dices := []Dices{Dices{1, 2, 3, 4, 6}, Dices{1, 1, 2, 3, 4}, Dices{2, 3, 4, 5, 6}, Dices{1, 2, 3, 3, 4}}
+	for _, d := range dices {
+		if !d.IsSmallStraight() {
+			t.Errorf("%v is a small straight", d)
+		}
+	}
+	dices = []Dices{Dices{1, 2, 3, 3, 5}, Dices{1, 4, 4, 5, 5}, Dices{1, 2, 2, 3, 6}, Dices{1, 1, 2, 5, 6}}
+	for _, d := range dices {
+		if d.IsSmallStraight() {
+			t.Errorf("%v is not a small straight", d)
+		}
+	}
+}
+
+func TestIsLargeStraight(t *testing.T) {
+	dices := []Dices{Dices{1, 2, 3, 4, 5}, Dices{2, 3, 4, 5, 6}}
+	for _, d := range dices {
+		if !d.IsLargeStraight() {
+			t.Errorf("%v is a large straight", d)
+		}
+	}
+	dices = []Dices{Dices{1, 2, 3, 3, 4}, Dices{1, 4, 4, 5, 5}, Dices{1, 2, 2, 3, 6}, Dices{1, 1, 2, 5, 6}}
+	for _, d := range dices {
+		if d.IsLargeStraight() {
+			t.Errorf("%v is not a large straight", d)
+		}
+	}
+}
+
+func TestIsYahtzee(t *testing.T) {
+	dices := []Dices{Dices{3, 3, 3, 3, 3}, Dices{1, 1, 1, 1, 1}}
+	for _, d := range dices {
+		if !d.IsYahtzee() {
+			t.Errorf("%v is a yahtzee", d)
+		}
+	}
+	dices = []Dices{Dices{1, 2, 3, 3, 4}, Dices{1, 4, 4, 5, 5}, Dices{1, 2, 2, 3, 6}, Dices{1, 1, 2, 5, 6}}
+	for _, d := range dices {
+		if d.IsYahtzee() {
+			t.Errorf("%v is not a yahtzee", d)
+		}
+	}
+}