數據結構----順序表與單鏈表（JAVA）

下面為學習順序表和單鏈表的一些基本操作函數：

public class SeqList<T> extends Object {
    protected int n;
    protected Object[] element;

    public SeqList(int length) {
        this.element = new Object[length];
        this.n = 0;
    }

    public SeqList() {
        this(64);
    }

    public SeqList(T[] values) {
        this(values.length);
        for (int i = 0; i < values.length; i++) {
            this.element[i] = values[i];
        }
        this.n = element.length;

    }

    public boolean isEmpty() {
        if (this.n == 0)
            return true;
        return false;
    }

    public int size() {
        return this.n;
    }

    public T get(int i) {
        if (i >= 0 && i < this.n) {
            return (T) this.element[i];
        }
        return null;
    }

    public void set(int i, T x) {
        if (x == null)
            throw new NullPointerException("x==null");
        if (i >= 0 && i < this.n)
            this.element[i] = x;
        else
            throw new java.lang.IndexOutOfBoundsException(i + "");
    }

    public int insert(int i, T x) { // 插入x元素
        if (x == null)
            throw new NullPointerException("x==null");
        if (i < 0)
            i = 0;
        if (i > this.n)
            i = this.n;
        Object[] source = this.element;
        if (this.n == element.length) {
            this.element = new Object[source.length * 2]; // 申請一個2倍大的數組
            for (int j = 0; j < i; j++) {
                this.element[j] = source[j];

            }
        }
        for (int j = this.n - 1; j >= i; j--) {
            element[j + 1] = source[j];

        }

        this.element[i] = x;
        this.n++;
        return i;
    }

    public int insert(T x) { // 表尾插入x元素，成員方法重載
        return this.insert(this.n, x);
    }

    public T remove(int i) { // 刪除數組下標為i的元素
        if (this.n >= 0 && i >= 0 && i < this.n) {
            T old = (T) this.element[i];
            for (int j = i; j < this.n - 1; j++) {
                element[j] = element[j + 1];

            }
            this.element[this.n - 1] = null;
            this.n--;
            return old;
        }
        return null;

    }

    public void clear() { // 刪除所有元素
        this.n = 0;
    }

public class Node<T> { // 結點類
    public T data;
    public Node<T> next;

    public Node(T data, Node<T> next) {
        this.data = data;
        this.next = next;
    }

    public Node() {
        this(null, null);
    }

}
public class SinglyList<T> extends Object {  //帶頭結點的單鏈表類
    public Node<T> head;

    public SinglyList() {
        this.head = new Node<T>();
    }

    public SinglyList(T[] values) {
        this();
        Node<T> rear = this.head;
        for (int i = 0; i < values.length; i++) {
            rear.next = new Node<T>(values[i], null);
            rear = rear.next;
        }
    }

    public boolean isEmpty() {
        return this.head.next == null;
    }

    public T get(int i) {
        Node<T> p = this.head.next;
        for (int j = 0; p != null && j < i; j++) {
            p = p.next;
        }
        return (i >= 0 && p != null) ? p.data : null;
    }

    public void set(int i, T x) {
        if (i < 0 || i > size())
            throw new IndexOutOfBoundsException(i + "");
        if (x == null)
            throw new NullPointerException("x==null");
        Node<T> p = this.head.next;
        for (int j = 0; p != null && j < i; j++) {
            p = p.next;
        }
        p.data = x;

    }

    public int size() {
        int len = 0;
        Node<T> p = this.head.next;
        if (p == null)
            return -1;
        while (p != null) {
            len++;
            p = p.next;

        }
        return len;
    }

    public Node<T> insert(int i, T x) {
        if (x == null)
            throw new NullPointerException("x==null");
        Node<T> front = this.head;
        for (int j = 0; front.next != null && j < i; j++) {
            front = front.next;
        }
        front.next = new Node<T>(x, front.next);
        return front.next;

    }

    public Node<T> insert(T t) {
        return insert(Integer.MAX_VALUE, t);
    }

    public T remove(int i) {
        Node<T> front = this.head;
        for (int j = 0; front.next != null && j < i; j++) {
            front = front.next;
        }
        if (i >= 0 && front.next != null) {
            T old = front.next.data;
            front.next = front.next.next;
            return old;
        }
        return null;

    }

    public void clear() {
        this.head.next = null;
    }

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