Merge pull request #331 from timwangmusic/sort-before-solve

[Enhancement] Sort places by score before solving combinatorics

matching/score.go

@@ -17,7 +17,7 @@ const (
 // TODO, RW: remove in the future
 func ScoreOld(places []Place) float64 {
 	if len(places) == 1 {
-		return singlePlaceScore(places[0])
+		return PlaceScore(places[0])
 	}
 	distances := calDistances(places)                     // Haversine distances
 	maxDist := math.Max(0.001, calMaxDistance(distances)) // protect against maximum distance being zero
@@ -30,7 +30,7 @@ func ScoreOld(places []Place) float64 {
 // Score uses constant distance normalisation factor
 func Score(places []Place, distNorm int) float64 {
 	if len(places) == 1 {
-		return singlePlaceScore(places[0])
+		return PlaceScore(places[0])
 	}
 	distances := calDistances(places)                            // Haversine distances
 	avgDistance := stat.Mean(distances, nil) / float64(distNorm) // normalized average distance
@@ -39,7 +39,7 @@ func Score(places []Place, distNorm int) float64 {
 	return avgScore - avgDistance
 }
 
-func singlePlaceScore(place Place) float64 {
+func PlaceScore(place Place) float64 {
 	var boostFactor float64
 	if place.PlacePrice() == 0 {
 		boostFactor = float64(place.Rating()) / MaxPlaceRating
@@ -70,7 +70,7 @@ func avgPlacesScore(places []Place) float64 {
 	numPlaces := len(places)
 	placeScores := make([]float64, numPlaces)
 	for k, place := range places {
-		placeScores[k] = singlePlaceScore(place)
+		placeScores[k] = PlaceScore(place)
 	}
 	return stat.Mean(placeScores, nil)
 }

matching/score_test.go

@@ -0,0 +1,43 @@
+package matching
+
+import (
+	"github.com/weihesdlegend/Vacation-planner/POI"
+	"testing"
+)
+
+func TestPlaceScore(t *testing.T) {
+	type args struct {
+		place Place
+	}
+	tests := []struct {
+		name string
+		args args
+		want float64
+	}{
+		{
+			name: "test compute place score with zero price should return correct result",
+			args: args{place: Place{
+				Place:    &POI.Place{Name: "Local Park", UserRatingsTotal: 99, Rating: 4.0},
+				Category: POI.PlaceCategoryVisit,
+				Price:    0,
+			}},
+			want: 1.6,
+		},
+		{
+			name: "test compute place score with price at level two should return correct result",
+			args: args{place: Place{
+				Place:    &POI.Place{Name: "Uncle Pizza", UserRatingsTotal: 999, Rating: 4.0},
+				Category: POI.PlaceCategoryEatery,
+				Price:    2,
+			}},
+			want: 6.0,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := PlaceScore(tt.args.place); got != tt.want {
+				t.Errorf("PlaceScore() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

planner/solver.go

@@ -1,6 +1,7 @@
 package planner
 
 import (
+	"cmp"
 	"container/heap"
 	"context"
 	"errors"
@@ -537,6 +538,8 @@ func (s *Solver) generatePlacesForSlots(ctx context.Context, req *PlanningReques
 		if len(placesByPrice) == 0 {
 			return nil, fmt.Errorf("failed to find any place for category %s at slot %s for location %+v", slot.Category, slot.TimeSlot.ToString(), req.Location)
 		}
+		// sort places by score descending so the solver checks places with higher score first
+		slices.SortFunc(placesByPrice, func(a, b matching.Place) int { return cmp.Compare(matching.PlaceScore(b), matching.PlaceScore(a)) })
 		placeClusters = append(placeClusters, placesByPrice)
 	}
 	return placeClusters, nil