diff --git a/tree/heap/heap.go b/tree/heap/heap.go
index b574056..e376c30 100644
--- a/tree/heap/heap.go
+++ b/tree/heap/heap.go
@@ -110,40 +110,28 @@ func (h *Heap) Pop() (interface{}, bool) {
 
 	downvalue := h.elements[h.size]
 	var cidx, c1, c2 int
-	var cvalue1, cvalue2, cvalue interface{}
 	// down
 	for {
 		cidx = curidx << 1
 
+		c1 = cidx + 1
 		c2 = cidx + 2
+
 		if c2 < h.size {
-			cvalue2 = h.elements[c2]
-
-			c1 = cidx + 1
-			cvalue1 = h.elements[c1]
-
-			if h.Compare(cvalue1, cvalue2) >= 0 {
+			if h.Compare(h.elements[c1], h.elements[c2]) >= 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 {
+			cidx = c1
+			if c1 >= h.size {
 				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
diff --git a/tree/heap/heap_test.go b/tree/heap/heap_test.go
index 5d085df..ab4251d 100644
--- a/tree/heap/heap_test.go
+++ b/tree/heap/heap_test.go
@@ -1,11 +1,64 @@
 package heap
 
 import (
+	"sort"
 	"testing"
 
 	"github.com/474420502/focus/compare"
+	"github.com/Pallinder/go-randomdata"
 )
 
+func TestHeapGrowSlimming(t *testing.T) {
+
+	for ii := 0; ii < 1000; ii++ {
+
+		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}
@@ -31,8 +84,44 @@ func TestHeapPushTopPop(t *testing.T) {
 	if h.Size() != 0 {
 		t.Error("heap size is not equals to zero")
 	}
+
+	h.Clear()
+
+	l = []int{3, 5, 2, 7, 1}
+
+	for _, v := range l {
+		h.Put(v)
+	}
+
+	sort.Slice(l, func(i, j int) bool {
+		if l[i] > l[j] {
+			return true
+		}
+		return false
+	})
+
+	for i := 0; !h.Empty(); i++ {
+		v, _ := h.Pop()
+		if l[i] != v {
+			t.Error("heap is error")
+		}
+	}
 }
 
+// func BenchmarkPush(b *testing.B) {
+// 	h := New(compare.Int)
+// 	b.N = 40000000
+// 	var results []int
+// 	for i := 0; i < b.N; i++ {
+// 		results = append(results, randomdata.Number(0, 1000000000))
+// 	}
+
+// 	b.ResetTimer()
+// 	for _, v := range results {
+// 		h.Put(v)
+// 	}
+// }
+
 // func Int(k1, k2 interface{}) int {
 // 	c1 := k1.(int)
 // 	c2 := k2.(int)