chore: 基础数据结构部分增加少量描述文字

Author: luzhipeng

thinkings/basic-data-structure-en.md

@@ -16,6 +16,8 @@ The non-linear structure contains tree, graph and so on.
 
 It should be noted that, the linear and non-linear date structures do NOT mean that the data in those structure are stored in a linear or non-linear on the hard disk. It is just a logic partition. For example, binary tree can be stored in array.
 
+Generally speaking, the data structure which has `pre` and `next` is linear.
+Such as Array and Linked List, actually the Linked List is  a kind of `Single Tree`。
 ### Array
 
 Array is the simplest data structure and is used in so many places. For example, array is perfectly appropriate to store a data list. And in fact, you can find array behind many other data structures.
@@ -306,6 +308,9 @@ BTW, you can find more details and algorithms in the charpter [binary tree trave
 
 Heap is a kind of priority queue which is built in many data structure. But unfortunately, JS does not have a native implementation of this data structure. However, it won't be a problem for understanding and using this structure.
 
+Note that: heap is not the only implementation of `priority queue`, there're a lot of more complex
+implementations
+
 Related algorithm:
 
 - [295.find-median-from-data-stream](../problems/295.find-median-from-data-stream.md)

thinkings/basic-data-structure.md

@@ -14,6 +14,8 @@
 
 需要注意的是，线性和非线性不代表存储结构是线性的还是非线性的，这两者没有任何关系，它只是一种逻辑上的划分。
 比如我们可以用数组去存储二叉树。
+
+一般而言，有前驱和后继的就是线性数据结构。比如数组和链表。其实一叉树就是链表。
 ### 数组
 
 数组是最简单的数据结构了，很多地方都用到它。 比如有一个数据列表等，用它是再合适不过了。
@@ -305,6 +307,8 @@ return, children, sibling也都是一个fiber，因此fiber看起来就是一个
 堆其实是一种优先级队列，在很多语言都有对应的内置数据结构，很遗憾javascript没有这种原生的数据结构。
 不过这对我们理解和运用不会有影响。
 
+需要注意的是优先队列不仅有堆一种，还有更复杂的，但是通常来说，我们会把两者做等价。
+
 相关算法：
 
 - [295.find-median-from-data-stream](../problems/295.find-median-from-data-stream.md)