Stack chain implementation

CodeAs follows:

<textarea cols="50" rows="15" name="code" class="cpp">Class cstacklinkimpl; <br/> class cstacknode {<br/> friend class cstacklinkimpl; <br/> PRIVATE: <br/> int data; <br/> cstacknode * link; <br/> Public: <br/> cstacknode (int d, cstacknode * l = NULL): Data (D), Link (l) {}< br/> ~ Cstacknode () {}< br/>}; <br/> class cstacklinkimpl {<br/> Public: <br/> cstacklinkimpl (): Top (null) {}< br/> ~ Cstacklinkimpl (); <br/> bool isempty () {return Top = NULL ;}< br/> int POP (); <br/> int gettop (); <br/> void push (INT value); <br/> PRIVATE: <br/> cstacknode * Top; <br/> };</textarea> <textarea cols="50" rows="15" name="code" class="cpp">Int cstacklinkimpl: Pop () {<br/> assert (! Isempty (); <br/> cstacknode * pnode = top; <br/> // Top = pnode-> link; <br/> // return pnode-> data; <br/> int value = pnode-> data; <br/> Top = pnode-> link; <br/> Delete pnode; <br/> return value; <br/>}< br/> void cstacklinkimpl: Push (INT value) {<br/> cstacknode * pnode = new cstacknode (value, top ); <br/> Top = pnode; <br/>}< br/> int cstacklinkimpl: gettop () {<br/> assert (! Isempty (); <br/> return top-> data; <br/>}< br/> cstacklinkimpl ::~ Cstacklinkimpl () {</P> <p> cstacknode * pnode; <br/> while (top! = NULL) {<br/> pnode = top; <br/> Top => link; <br/> Delete pnode; <br/>}< br/>}</textarea>

 

In this process, I learned the following:

1. usage of the friend class. To allow Class A to have higher access permissions to Class B, it is necessary to point out in the declaration or definition of Class B that Class A is its friend class.

2. Top is the stack top, and push and pop change is the top. This is the stack idea.

3. Pay attention to releasing resources during pop. (The commented-out code is problematic)

4. Implementation of one-way linked list.