前期写过一个PHP实现单向链表、实现排序单向链表的一篇文章,传送门:http://www.cnblogs.com/yydcdut/p/3777760.html。双向链表写过了,再拿出来提一提:http://www.cnblogs.com/yydcdut/p/3782661.html。
这次再来分享一下实现双向链表和栈的实现。代码虽然是以前写的了,但是发现PHP写的这些代码很容易看懂!
双向链表
<?<span>php </span><span>//</span><span>双向链表</span> <span>class</span><span> Hero { </span><span>public</span> <span>$pre</span>=<span>null</span>;<span>//</span><span>前指针</span> <span>public</span> <span>$no</span>;<span>//</span><span>排名</span> <span>public</span> <span>$name</span>;<span>//</span><span>名字</span> <span>public</span> <span>$next</span>=<span>null</span>;<span>//</span><span>后指针</span> <span>/*</span><span>* *构造函数,申明链表头 </span><span>*/</span> <span>public</span> <span>function</span> __construct(<span>$no</span>='',<span>$name</span>=''<span>) { </span><span>$this</span>->no=<span>$no</span><span>; </span><span>$this</span>->name=<span>$name</span><span>; } </span><span>/*</span><span>* *插入 </span><span>*/</span> <span>static</span> <span>public</span> <span>function</span> addHero(<span>$head</span>,<span>$hero</span><span>) { </span><span>$cur</span> = <span>$head</span><span>; </span><span>$isExist</span>=<span>false</span><span>; </span><span>//</span><span>判断目前这个链表是否为空</span> <span>if</span>(<span>$cur</span>-><span>next</span>==<span>null</span><span>) { </span><span>$cur</span>-><span>next</span>=<span>$hero</span><span>; </span><span>$hero</span>->pre=<span>$cur</span><span>; } </span><span>else</span><span> { </span><span>//</span><span>如果不是空节点,则安排名来添加 //找到添加的位置 </span> <span>while</span>(<span>$cur</span>-><span>next</span>!=<span>null</span><span>) { </span><span>if</span>(<span>$cur</span>-><span>next</span>->no > <span>$hero</span>-><span>no) {</span><span>//</span><span>如果大于了排名,跳出</span> <span>break</span><span>; } </span><span>else</span> <span>if</span>(<span>$cur</span>-><span>next</span>->no == <span>$hero</span>-><span>no) {</span><span>//</span><span>如果等于排名,则代表有这个元素了</span> <span>$isExist</span>=<span>true</span><span>; </span><span>echo</span> "<br>不能添加相同的编号"<span>; } </span><span>$cur</span>=<span>$cur</span>-><span>next</span><span>; } </span><span>if</span>(!<span>$isExist</span><span>) {</span><span>//</span><span>如果元素不存在,执行插入操作</span> <span>if</span>(<span>$cur</span>-><span>next</span>!=<span>null</span><span>) {</span><span>$hero</span>-><span>next</span>=<span>$cur</span>-><span>next</span><span>;} </span><span>$hero</span>->pre=<span>$cur</span><span>; </span><span>if</span>(<span>$cur</span>-><span>next</span>!=<span>null</span><span>) {</span><span>$hero</span>-><span>next</span>->pre=<span>$hero</span><span>;} </span><span>$cur</span>-><span>next</span>=<span>$hero</span><span>; } } } </span><span>//</span><span>遍历</span> <span>static</span> <span>public</span> <span>function</span> showHero(<span>$head</span><span>) { </span><span>$cur</span>=<span>$head</span><span>; </span><span>while</span>(<span>$cur</span>-><span>next</span>!=<span>null</span><span>) { </span><span>echo</span> "<br>编号:".<span>$cur</span>-><span>next</span>->no."名字:".<span>$cur</span>-><span>next</span>-><span>name; </span><span>$cur</span>=<span>$cur</span>-><span>next</span><span>; } } </span><span>static</span> <span>public</span> <span>function</span> delHero(<span>$head</span>,<span>$herono</span><span>) { </span><span>$cur</span>=<span>$head</span><span>; </span><span>$isFind</span>=<span>false</span><span>; </span><span>while</span>(<span>$cur</span>!=<span>null</span><span>) { </span><span>if</span>(<span>$cur</span>->no==<span>$herono</span><span>) { </span><span>$isFind</span>=<span>true</span><span>; </span><span>break</span><span>; } </span><span>//</span><span>继续找</span> <span>$cur</span>=<span>$cur</span>-><span>next</span><span>; } </span><span>if</span>(<span>$isFind</span><span>) { </span><span>if</span>(<span>$cur</span>-><span>next</span>!=<span>null</span><span>) {</span><span>$cur</span>->next_pre=<span>$cur</span>-><span>pre;} </span><span>$cur</span>->pre-><span>next</span>=<span>$cur</span>-><span>next</span><span>; } </span><span>else</span><span> {</span><span>echo</span> "<br>没有找到目标"<span>;} } } </span><span>$head</span> = <span>new</span><span> Hero(); </span><span>$hero1</span> = <span>new</span> Hero(1,'1111'<span>); </span><span>$hero3</span> = <span>new</span> Hero(3,'3333'<span>); </span><span>$hero2</span> = <span>new</span> Hero(2,'2222'<span>); Hero</span>::addHero(<span>$head</span>,<span>$hero1</span><span>); Hero</span>::addHero(<span>$head</span>,<span>$hero3</span><span>); Hero</span>::addHero(<span>$head</span>,<span>$hero2</span><span>); Hero</span>::showHero(<span>$head</span><span>); Hero</span>::delHero(<span>$head</span>,2<span>); Hero</span>::showHero(<span>$head</span><span>); </span>?>
双向链表的插入操作示意图:
<span>if</span>(<span>$cur</span>-><span>next</span>!=<span>null</span><span>) </span><span>$hero</span>-><span>next</span>=<span>$cur</span>-><span>next</span><span>; </span><span>$hero</span>->pre=<span>$cur</span><span>; </span><span>if</span>(<span>$cur</span>-><span>next</span>!=<span>null</span><span>) </span><span>$hero</span>-><span>next</span>->pre=<span>$hero</span><span>; </span><span>$cur</span>-><span>next</span>=<span>$hero</span>;
if($cur->next!=null) $cur->next->pre=$cur->pre; $cur->pre->next=$cur->next;
栈
<?<span>php </span><span>class</span><span> myStack { </span><span>private</span> <span>$top</span>=-1<span>; </span><span>private</span> <span>$maxSize</span>=5<span>; </span><span>private</span> <span>$stack</span>=<span>array</span><span>(); </span><span>public</span> <span>function</span> push(<span>$val</span><span>) { </span><span>if</span>(<span>$this</span>->top == <span>$this</span>-><span>maxSize) { </span><span>echo</span> "<br>已经满了"<span>; } </span><span>$this</span>->top++<span>; </span><span>$this</span>->stack[<span>$this</span>->top]=<span>$val</span><span>; } </span><span>public</span> <span>function</span><span> showStack() { </span><span>if</span>(<span>$this</span>->top==-1<span>) { </span><span>echo</span> "<br>栈为空!"<span>; </span><span>return</span><span> ; } </span><span>for</span>(<span>$i</span>=<span>$this</span>->top;<span>$i</span>>-1;<span>$i</span>--<span>) { </span><span>echo</span> "<br>stack[".<span>$i</span>."]=".<span>$this</span>->stack[<span>$i</span><span>]; } } </span><span>public</span> <span>function</span><span> pop() { </span><span>if</span>(<span>$this</span>->top==-1<span>) { </span><span>echo</span> "<br>栈为空!"<span>; </span><span>return</span><span> ; } </span><span>$val</span>=<span>$this</span>->stack[<span>$this</span>-><span>top]; </span><span>$this</span>->top--<span>; </span><span>echo</span> "<br>弹出".<span>$val</span><span>; } } </span><span>$mystack</span> = <span>new</span><span> myStack; </span><span>$mystack</span>->push('111'<span>); </span><span>$mystack</span>->push('222'<span>); </span><span>$mystack</span>-><span>showStack(); </span><span>$mystack</span>-><span>pop(); </span><span>$mystack</span>-><span>pop(); </span>?>
我是天王盖地虎的分割线
《PHP实现链表》传送门:http://www.cnblogs.com/yydcdut/p/3777760.html
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