fix some bug and add cap method to array

heap/heap.go

@@ -2,15 +2,18 @@ package heap
 
 import (
 	"474420502.top/eson/structure/compare"
+	"474420502.top/eson/structure/sparse_array/array3"
 )
 
 type Heap struct {
 	size     int
 	cap      int
-	elements []interface{}
+	elements *array3.Array3
 	Compare  compare.Compare
 }
 
 func New(Compare compare.Compare) *Heap {
-	return &Heap{Compare: Compare, cap: 8}
+	h := &Heap{Compare: Compare, cap: 8}
+	h.elements = array3.NewWithCap(4, 4, 4)
+	return h
 }