89 lines
2.1 KiB
Java
89 lines
2.1 KiB
Java
/*
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* File: array_stack.java
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* Created Time: 2022-11-25
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* Author: Krahets (krahets@163.com)
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*/
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package chapter_stack_and_queue;
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import java.util.*;
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/* 基于数组实现的栈 */
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class ArrayStack {
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private ArrayList<Integer> stack;
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public ArrayStack() {
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// 初始化列表（动态数组）
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stack = new ArrayList<>();
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}
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/* 获取栈的长度 */
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public int size() {
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return stack.size();
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}
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/* 判断栈是否为空 */
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public boolean isEmpty() {
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return size() == 0;
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}
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/* 入栈 */
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public void push(int num) {
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stack.add(num);
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}
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/* 出栈 */
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public int pop() {
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return stack.remove(size() - 1);
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}
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/* 访问栈顶元素 */
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public int peek() {
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return stack.get(size() - 1);
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}
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/* 访问索引 index 处元素 */
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public int get(int index) {
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return stack.get(index);
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}
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/* 将 List 转化为 Array 并返回 */
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public Object[] toArray() {
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return stack.toArray();
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}
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}
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public class array_stack {
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public static void main(String[] args) {
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/* 初始化栈 */
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ArrayStack 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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System.out.println("栈 stack = " + Arrays.toString(stack.toArray()));
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/* 访问栈顶元素 */
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int peek = stack.peek();
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System.out.println("栈顶元素 peek = " + peek);
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/* 访问索引 index 处元素 */
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int num = stack.get(3);
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System.out.println("栈索引 3 处的元素为 num = " + num);
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/* 元素出栈 */
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int pop = stack.pop();
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System.out.println("出栈元素 pop = " + pop + "，出栈后 stack = " + Arrays.toString(stack.toArray()));
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/* 获取栈的长度 */
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int size = stack.size();
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System.out.println("栈的长度 size = " + size);
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/* 判断是否为空 */
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boolean isEmpty = stack.isEmpty();
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System.out.println("栈是否为空 = " + isEmpty);
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}
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}
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