92 lines
1.7 KiB
PHP
92 lines
1.7 KiB
PHP
<?php
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/**
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* File: array_stack.php
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* Created Time: 2024-05-19
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* Author: DoWake (admin@mengxing.cc)
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*/
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/* 基于数组实现的栈 */
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class ArrayStack
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{
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private $stack;
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/* 构造方法 */
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public function __construct()
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{
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// 初始化列表（动态数组）
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$this->stack = [];
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}
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/* 获取栈的长度 */
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public function size()
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{
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return count($this->stack);
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}
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/* 判断栈是否为空 */
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public function isEmpty()
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{
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return $this->size() === 0;
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}
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/* 入栈 */
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public function push($num)
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{
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array_push($this->stack, $num);
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}
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/* 出栈 */
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public function pop()
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{
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if ($this->isEmpty()) {
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throw new Exception('The Stack Is Empty.');
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}
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return array_pop($this->stack);
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}
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/* 访问栈顶元素 */
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public function peek()
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{
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if ($this->isEmpty()) {
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throw new Exception('The Stack Is Empty.');
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}
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return end($this->stack);
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}
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/* 将 List 转化为 Array 并返回 */
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public function toArray()
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{
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return $this->stack;
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}
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}
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/* Driver Code */
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/* 初始化栈 */
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$stack = new ArrayStack();
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/* 元素入栈 */
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$stack->push(1);
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$stack->push(3);
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$stack->push(2);
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$stack->push(5);
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$stack->push(4);
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echo '栈 stack = [' . join(', ', $stack->toArray()) . ']' . PHP_EOL;
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/* 访问栈顶元素 */
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$peek = $stack->peek();
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echo "栈顶元素 peek = {$peek}" . PHP_EOL;
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/* 元素出栈 */
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$pop = $stack->pop();
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echo "出栈元素 pop = {$pop}，出栈后 stack = [" . join(', ', $stack->toArray()) . ']' . PHP_EOL;
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/* 获取栈的长度 */
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$size = $stack->size();
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echo "栈的长度 size = {$size}" . PHP_EOL;
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/* 判断是否为空 */
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$isEmpty = $stack->isEmpty();
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$isEmptyStr = $isEmpty ? 'true' : 'false';
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echo "栈是否为空 = {$isEmptyStr}" . PHP_EOL;
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