Fix for shanten bug

Author: dnovikoff

hand/calc/calculator_test.go

@@ -54,3 +54,15 @@ func TestCalculatorShanten(t *testing.T) {
 		"11m [23m (14m)] ",
 	}, tr.records)
 }
+
+func TestCalculatorShantenTankiBug(t *testing.T) {
+	tg := compact.NewTestGenerator(t)
+	hand := tg.CompactFromString("23m11112222333z")
+	tr := &testResults{}
+	opts := GetOptions(SetResults(tr), Opened(0))
+	fm := FilterMelds(hand, CreateAll())
+	Calculate(fm, hand, opts)
+	assert.Equal(t, []string{
+		"nil [23m (14m) 111z 222z 333z] 12z",
+	}, tr.records)
+}

hand/shanten/result.go

@@ -82,8 +82,22 @@ func (r *calcResult) Record(in *calc.ResultData) {
 	fullSets := in.Sets > 3
 
 	if in.Pair == nil {
+		var tankiImproves compact.Tiles
 		for _, t := range in.Left {
-			improves = improves.Set(t)
+			tankiImproves = tankiImproves.Set(t)
+		}
+		var tankiLocked compact.Tiles
+		for _, v := range in.Closed {
+			if v.Tags().CheckAny(calc.TagPon) {
+				tankiLocked = tankiLocked.Set(v.Tile())
+			}
+		}
+		tankiLeft := tankiImproves.Sub(tankiLocked)
+		if tankiLeft.IsEmpty() {
+			value++
+			improves = improves.Merge(compact.AllTiles.Sub(tankiLocked))
+		} else {
+			improves = improves.Merge(tankiLeft)
 		}
 	}
 

hand/shanten/shanten_test.go

@@ -116,13 +116,22 @@ func TestShantenBug1(t *testing.T) {
 	assert.Equal(t, "1369m179p19s1234567z", uke.UniqueTiles().Tiles().String())
 }
 
+func TestShantenBug2(t *testing.T) {
+	tiles := testCompact(t, "23m111122223333z")
+	res := Calculate(tiles)
+	m := res.Total
+	assert.Equal(t, 2, m.Value)
+	uke := m.CalculateUkeIre(compact.NewTotals().Merge(tiles))
+	assert.Equal(t, "123456789m123456789p123456789s4567z", uke.UniqueTiles().Tiles().String())
+}
+
 func TestMonocolorBug(t *testing.T) {
-	tiles := testCompact(t, "1111222235555m")
+	tiles := testCompact(t, "1111222235555m1z")
 	res := Calculate(tiles)
 	m := res.Total
-	assert.Equal(t, 1, m.Value)
+	assert.Equal(t, 0, m.Value)
 	uke := m.CalculateUkeIre(compact.NewTotals().Merge(tiles))
-	assert.Equal(t, "3467m", uke.UniqueTiles().Tiles().String())
+	assert.Equal(t, "1z", uke.UniqueTiles().Tiles().String())
 }
 
 func TestImprovesPair(t *testing.T) {