restructured data-structures folder, changed heap_test.go to external tests (package -> heap_test)

2018/day22/main.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/alexchao26/advent-of-code-go/datastructures"
+	"github.com/alexchao26/advent-of-code-go/data-structures/heap"
 	"github.com/alexchao26/advent-of-code-go/util"
 )
 
@@ -114,7 +114,7 @@ func part2(input string) int {
 	depth, targetX, targetY := parseInput(input)
 	regionCalculator := memoRegionTypeCalculator(depth, targetX, targetY)
 
-	heap := datastructures.NewMinHeap()
+	heap := heap.NewMinHeap()
 	firstNode := node{
 		coords:     [2]int{0, 0},
 		regionType: regionCalculator(0, 0),
@@ -171,7 +171,7 @@ func (n node) Value() int {
 	return n.totalTime
 }
 
-func step(heap *datastructures.MinHeap, eqCoordsToMinDist map[equipmentType]map[[2]int]int, regionCalculator func(x, y int) regionType) node {
+func step(heap *heap.MinHeap, eqCoordsToMinDist map[equipmentType]map[[2]int]int, regionCalculator func(x, y int) regionType) node {
 	// remove node from heap, this will be returned at the end
 	minNodeInterface := heap.Remove()
 	if minNodeInterface == nil {

data-structures/heap/heap.go

@@ -1,4 +1,4 @@
-package datastructures
+package heap
 
 // MinHeap is an implementation of a min heap
 type MinHeap struct {
@@ -47,6 +47,14 @@ type heapNode interface {
 	Value() int
 }
 
+// Front returns the first node in the heap, nil if the heap is empty
+func (h *heap) Front() heapNode {
+	if len(h.nodes) == 0 {
+		return nil
+	}
+	return h.nodes[0]
+}
+
 // Add appends a new node onto the heap and heapifies it
 // to ensure correct ordering
 func (h *heap) Add(newNode heapNode) {

data-structures/heap/heap_test.go

@@ -1,7 +1,9 @@
-package datastructures
+package heap_test
 
 import (
 	"testing"
+
+	"github.com/alexchao26/advent-of-code-go/data-structures/heap"
 )
 
 type mockNode int
@@ -11,21 +13,26 @@ func (n mockNode) Value() int {
 }
 
 func TestMinHeap(t *testing.T) {
-	h := NewMinHeap()
+	h := heap.NewMinHeap()
 	h.Add(mockNode(5))
 	h.Add(mockNode(93))
 
-	if h.nodes[0].Value() != 5 {
-		t.Errorf("After adding 5, h.nodes[0].Value() = %d, want 5", h.nodes[0].Value())
+	if h.Front().(mockNode).Value() != 5 {
+		t.Errorf("After adding 5, h.Front().Value() = %d, want 5", h.Front().Value())
 	}
-	if h.nodes[1].Value() != 93 {
-		t.Errorf("After adding 93, h.nodes[1].Value() = %d, want 93", h.nodes[1].Value())
+	if h.Front().(mockNode).Value() != 5 {
+		t.Errorf("After adding 5 & 93, h.Front() = %d, want 5", h.Front().Value())
 	}
 
 	// Add a bunch of nodes, make sure they are removed in order
 	h.Add(mockNode(10))
 	h.Add(mockNode(2))
 	h.Add(mockNode(1))
+
+	if h.Front().(mockNode).Value() != 1 {
+		t.Errorf("After adding 5, 93, 10, 2 & 1, h.Front() = %d, want 1", h.Front().Value())
+	}
+
 	h.Add(mockNode(3))
 	h.Add(mockNode(4))
 	h.Add(mockNode(123))
@@ -41,15 +48,15 @@ func TestMinHeap(t *testing.T) {
 }
 
 func TestMaxHeap(t *testing.T) {
-	h := NewMaxHeap()
+	h := heap.NewMaxHeap()
 	h.Add(mockNode(5))
 	h.Add(mockNode(93))
 
-	if h.nodes[0].Value() != 93 {
-		t.Errorf("After adding 93, h.nodes[0].Value() = %d, want 93", h.nodes[1].Value())
+	if h.Front().Value() != 93 {
+		t.Errorf("After adding 93, h.Front().Value() = %d, want 93", h.Front().Value())
 	}
-	if h.nodes[1].Value() != 5 {
-		t.Errorf("After adding 5, h.nodes[1].Value() = %d, want 5", h.nodes[0].Value())
+	if h.Front().Value() != 93 {
+		t.Errorf("After adding 93 & 5, h.Front().Value() = %d, want 93", h.Front().Value())
 	}
 
 	// Add a bunch of nodes, make sure they are removed in order
@@ -59,6 +66,10 @@ func TestMaxHeap(t *testing.T) {
 	h.Add(mockNode(3))
 	h.Add(mockNode(4))
 	h.Add(mockNode(123))
+	if h.Front().(mockNode).Value() != 123 {
+		t.Errorf("After adding 5, 93, 10, 2, 1, 3, 4 & 123, h.Front() = %d, want 123", h.Front().Value())
+	}
+
 	h.Add(mockNode(32))
 	h.Add(mockNode(-15))