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php 实现堆栈实现

2026-02-28 05:28:12PHP

堆栈的基本概念

堆栈（Stack）是一种遵循后进先出（LIFO）原则的数据结构。主要操作包括压栈（push）和弹栈（pop），通常还会提供查看栈顶元素（peek）和判断栈是否为空（isEmpty）的方法。

使用数组实现堆栈

PHP的数组可以动态调整大小，非常适合用来实现堆栈。以下是一个简单的堆栈实现示例：

class Stack {
    private $stack;
    private $size;

    public function __construct() {
        $this->stack = array();
        $this->size = 0;
    }

    public function push($element) {
        array_push($this->stack, $element);
        $this->size++;
    }

    public function pop() {
        if ($this->isEmpty()) {
            throw new RuntimeException("Stack is empty");
        }
        $this->size--;
        return array_pop($this->stack);
    }

    public function peek() {
        if ($this->isEmpty()) {
            throw new RuntimeException("Stack is empty");
        }
        return $this->stack[$this->size - 1];
    }

    public function isEmpty() {
        return $this->size === 0;
    }

    public function size() {
        return $this->size;
    }
}

堆栈的使用示例

创建堆栈实例并进行操作：

$stack = new Stack();
$stack->push(10);
$stack->push(20);
$stack->push(30);

echo $stack->pop();  // 输出 30
echo $stack->peek(); // 输出 20
echo $stack->size(); // 输出 2

使用链表实现堆栈

链表也可以用来实现堆栈，适合需要更灵活内存管理的场景。以下是链表实现的示例：

class Node {
    public $data;
    public $next;

    public function __construct($data) {
        $this->data = $data;
        $this->next = null;
    }
}

class LinkedListStack {
    private $top;
    private $size;

    public function __construct() {
        $this->top = null;
        $this->size = 0;
    }

    public function push($element) {
        $newNode = new Node($element);
        $newNode->next = $this->top;
        $this->top = $newNode;
        $this->size++;
    }

    public function pop() {
        if ($this->isEmpty()) {
            throw new RuntimeException("Stack is empty");
        }
        $data = $this->top->data;
        $this->top = $this->top->next;
        $this->size--;
        return $data;
    }

    public function peek() {
        if ($this->isEmpty()) {
            throw new RuntimeException("Stack is empty");
        }
        return $this->top->data;
    }

    public function isEmpty() {
        return $this->top === null;
    }

    public function size() {
        return $this->size;
    }
}