数据结构之栈

Posted 2020-10-04 宋发准

  1 package com.fz.song.stack;
  2 
  3 /**
  4  * Created by sfz on 2017/8/29.
  5  */
  6 public class MyStack {
  7 
  8     //长度
  9     private int size;
 10     //数组
 11     private int[] data;
 12     //栈顶
 13     private int top;
 14 
 15     public MyStack(int size) {
 16         this.size = size;
 17         data = new int[size];
 18         top = 0;
 19     }
 20 
 21     /**
 22      * 判断是否为空
 23      *
 24      * @return
 25      */
 26     public boolean isEmpty() {
 27         return 0 == top;
 28     }
 29 
 30     /**
 31      * 判满
 32      *
 33      * @return
 34      */
 35     public boolean isFull() {
 36         return (0 != size && size == top);
 37     }
 38 
 39 
 40     /**
 41      * 清空栈
 42      *
 43      * @return
 44      */
 45     public boolean cleanStack() {
 46         if (isEmpty()) {
 47             return false;
 48         } else {
 49             top = 0;
 50             return true;
 51         }
 52     }
 53 
 54     /**
 55      * 获取长度
 56      *
 57      * @return
 58      */
 59     public int length() {
 60         return top;
 61     }
 62 
 63 
 64     /**
 65      * 入栈
 66      *
 67      * @param elem
 68      * @return
 69      */
 70     public boolean push(int elem) {
 71 
 72         if (isFull()) {
 73             return false;
 74         } else {
 75             data[top] = elem;
 76             top++;
 77             return true;
 78         }
 79     }
 80 
 81     /**
 82      * 出栈
 83      *
 84      * @return
 85      */
 86     public int pop() throws Exception {
 87 
 88         if (isEmpty()) {
 89             throw new Exception("当前栈为空");
 90         } else {
 91             top--;
 92             int val = data[top];
 93             return val;
 94         }
 95     }
 96 
 97     /**
 98      * 遍历栈元素
 99      */
100     public void each() {
101         for (int i = 0; i < top; i++) {
102             System.out.print(data[i] + "  ");
103         }
104         System.out.println("");
105     }
106 
107 }