博主最近换了家新公司，刚进去很是清闲，IT这行业发展太迅速，没事干就得学习，不断学习，看过了许多源码之后，开始自己写一些简单的java源码，巩固一下自己的记忆。先从一些简单的数据结构开始！
一 数组实现栈结构
public class MyStack {
private long[] a;
private int size;//栈数组大小
private int top;//栈顶指针
public MyStack(int size) {
this.a = new long[size];
this.size = size;
this.top = -1; //表示空栈
}
public void push(long value) {
if (isFull()) {
System.out.println("栈满了");
return;
}
this.a[++top] = value;
}
//返回栈顶内容 但不删除
public long peek() {
if (isEmpty()) {
System.out.println("栈中没有数据");
return 0;
}
return a[top];
}
//返回栈顶内容 并删除
public long pop() {
if (isEmpty()) {
System.out.println("栈中没有数据");
return 0;
}
return a[top--];
}
//栈实际大小
public int size() {
return top + 1;
}
public boolean isFull() {
return top == size - 1;
}
public boolean isEmpty() {
return top == -1;
}
public void display() {
for (int i = top;i >= 0;i --) {
System.out.println(a[i] + " ");
}
}
}二 循环数组实现一个队列
public class MyQueue {
private long[] a; //循环数组实现！
private int maxSize; //总共大小
private int size; //实际大小
private int front; //队头
private int rear; //队尾
public MyQueue(int maxSize) {
this.a = new long[maxSize];
this.maxSize = maxSize;
this.size = 0;
this.front = 0;
this.rear = 0;
}
public void insert(long value) {
if (isFull()) {
System.out.println("队列已满");
return;
}
rear = ++ rear % maxSize;
a[rear] = value;
size ++;
// //如果队列已满 则回到队头
// if (rear == size - 1) {
// rear = -1;
// }
// a[++ rear] = value;
}
public long remove() {
if (isEmpty()) {
System.out.println("队列为空");
return 0;
}
size --;
front = front % maxSize;
return a[front++];
}
public long peek() {
if (isEmpty()) {
System.out.println("队列为空");
return 0;
}
return a[front];
}
public boolean isFull() {
return size == maxSize;
}
public boolean isEmpty() {
return size == 0;
}
public int size() {
return size;
}
public void display() {
if (isEmpty()) {
System.out.println("队列为空");
return;
}
int item = front;
for (int i = 0;i < size;i++) {
System.out.println(a[item ++ % maxSize] + " ");
}
}
}三 单向链表的简单实现
public class MyLNode { //节点实体
public int data; //节点值
public MyLNode next; //节点指向的下一节点
public MyLNode(int data) {
this(data, null);
}
public MyLNode(int data, MyLNode node) {
this.data = data;
this.next = node;
}
}public class MyLinkedList {//单向链表
private int size; //链表大小
public MyLNode head; // 头结点
public MyLNode tail; //尾结点
public MyLinkedList() {
this.head = null;
this.tail = null;
}
public boolean isEmpty() {
return head == null;
}
public void addToHead(int value) {//向头部添加节点
MyLNode temp = new MyLNode(value, head);
head = temp;
if (tail == null) {
tail = head;
}
size ++;
}
public void addToTail(int value) {//向尾部添加节点
MyLNode temp = new MyLNode(value);
if (isEmpty()) {
head = tail = temp;
} else {
tail.next = temp;
tail = tail.next;
}
size ++;
}
public int deleteToHead() {//删除头结点
if (isEmpty()) {
System.out.println("链表为空");
return -1;
}
int data = head.data;
if (head == tail) { //头尾指向一个节点
head = tail = null;
} else {
head = head.next;
}
size --;
return data;
}
public int deleteToTail() {//删除尾结点
if (isEmpty()) {
System.out.println("链表为空");
return -1;
}
int data = tail.data;
if (head == tail) { //头尾指向一个节点
head = tail = null;
} else {
MyLNode temp;
for (temp = head;temp.next != tail;temp = temp.next); //循环找到尾结点的前一节点
tail = temp;
tail.next = null;
}
size --;
return data;
}
public void delete(int value) {//删除value节点
if (isEmpty()) {
System.out.println("链表为空");
return;
}
if (head.data == value) {//如果是头结点
deleteToHead();
} else if (tail.data == value) {//如果是尾结点
deleteToTail();
} else {
MyLNode pre; //记录删除节点的前一节点
MyLNode temp; //要删除的节点
for (pre = head,temp = head.next;temp.data != value && temp.next != null;temp = temp.next,pre = pre.next) {
if (temp == tail) {
System.out.println(value + "该节点不存在！");
} else {
pre.next = temp.next;
}
}
}
size --;
}
public void insert(int value,int val) {//插入到value值之后
if (isEmpty()) {
System.out.println("链表为空");
return;
}
if (head.data == value) {//如果是头结点
addToHead(val);
} else if (tail.data == value) {//如果是尾结点
addToTail(val);
} else {
MyLNode temp; //要添加节点的之前节点
for (temp = head.next;temp.data != value && temp.next != null;temp = temp.next) {
if (temp == tail) {
System.out.println(value + "该节点不存在！");
} else {
MyLNode node = new MyLNode(val, temp.next);
temp.next = node;
}
}
}
size ++;
}
public int size() {
return size;
}
public void show() {
for(MyLNode temp = head;temp != null;temp = temp.next)
System.out.print(temp.data + " ");
}
}
如果有什么错误，或者更好的方式，欢迎大家指出！