优化heap

tree/heap/heap.go

@@ -110,40 +110,37 @@ func (h *Heap) Pop() (interface{}, bool) {
 
 	downvalue := h.elements[h.size]
 	var cidx, c1, c2 int
-	var cvalue1, cvalue2, cvalue interface{}
+	var cvalue1, cvalue2 interface{}
 	// down
 	for {
 		cidx = curidx << 1
 
-		c2 = cidx + 2
-		if c2 < h.size {
-			cvalue2 = h.elements[c2]
-
 		c1 = cidx + 1
+		c2 = cidx + 2
+
+		if c2 < h.size {
+
+			cvalue2 = h.elements[c2]
 			cvalue1 = h.elements[c1]
 
 			if h.Compare(cvalue1, cvalue2) >= 0 {
 				cidx = c1
-				cvalue = cvalue1
 			} else {
 				cidx = c2
-				cvalue = cvalue2
 			}
 		} else {
 
-			c1 = cidx + 1
 			if c1 < h.size {
 				cvalue1 = h.elements[c1]
 				cidx = c1
-				cvalue = cvalue1
 			} else {
 				break
 			}
 
 		}
 
-		if h.Compare(cvalue, downvalue) > 0 {
-			h.elements[curidx] = cvalue
+		if h.Compare(h.elements[cidx], downvalue) > 0 {
+			h.elements[curidx] = h.elements[cidx]
 			curidx = cidx
 		} else {
 			break

tree/heap/heap_test.go

@@ -1,11 +1,60 @@
 package heap
 
 import (
+	"sort"
 	"testing"
 
 	"github.com/474420502/focus/compare"
+	"github.com/Pallinder/go-randomdata"
 )
 
+func TestHeapGrowSlimming(t *testing.T) {
+	h := New(compare.Int)
+	var results []int
+	for i := 0; i < 100; i++ {
+		v := randomdata.Number(0, 100)
+		results = append(results, v)
+		h.Put(v)
+	}
+	sort.Slice(results, func(i, j int) bool {
+		if results[i] > results[j] {
+			return true
+		}
+		return false
+	})
+
+	if h.Size() != 100 || h.Empty() {
+		t.Error("size != 100")
+	}
+
+	for i := 0; !h.Empty(); i++ {
+		v, _ := h.Pop()
+		if results[i] != v {
+			t.Error("heap is error")
+		}
+	}
+
+	if h.Size() != 0 {
+		t.Error("size != 0")
+	}
+
+	h.Put(1)
+	h.Put(5)
+	h.Put(2)
+
+	if h.Values()[0] != 5 {
+		t.Error("top is not equal to 5")
+	}
+
+	h.Clear()
+	h.Reborn()
+
+	if !h.Empty() {
+		t.Error("clear reborn is error")
+	}
+
+}
+
 func TestHeapPushTopPop(t *testing.T) {
 	h := New(compare.Int)
 	l := []int{9, 5, 15, 2, 3}