01--图解数据结构之数组实现集合

/**
 * 作者：张风捷特烈
 * 时间：2018/9/19 0019:8:59
 * 邮箱：1981462002@qq.com
 * 说明：数组测试
 */
public class ClientOfArray {

    public static void main(String[] args) {
        //生成数组--方式1
        int[] id = new int[5];
        for (int i = 0; i < id.length; i++) {
            id[i] = i;
        }

        //生成数组--方式2
        String[] name = new String[]{"张", "风", "捷", "特", "烈"};
        for (int i = 0; i < name.length; i++) {
            System.out.print(name[i]);//张风捷特烈
        }
        //增强for循环
        for (String str : name) {
            System.out.print(str);//张风捷特烈
        }
    }
}

/**
 * 成员数组
 */
private T[] datas;

/**
 * 无参构造--默认容量10
 */
public ArrayGroup() {
    this(10);
}

/**
 * 一参构造
 * @param capacity 集合容量
 */
public ArrayGroup(int capacity) {
    //实例化数组
    datas = (T[]) new Object[capacity];
}

 @Override
 public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append(String.format("ArrayGroup:size =%d,capacity=%d\n",size,datas.length));
     sb.append("[");
     for (int i = 0; i < size; i++) {
         sb.append(datas[i].toString());
         if (i != size - 1) {
             sb.append(", ");
         }
     }
     sb.append("]");

@Override
public void add(int index, T el) {
    if (size == datas.length) {
        throw new IllegalArgumentException("Add failed! Array is full");
    }
    if (index < 0 || index > size) {
        throw new IllegalArgumentException("Add failed! Make sure index < 0 || index > size");
    }
    //从最后一个元素开始,到定点位置元素,后移一位
    for (int i = size-1; i >=index ; i--) {
        datas[i + 1] = datas[i];
    }
    datas[index] = el;
    size++;
}

 ArrayGroup<String> arrayGroup = new ArrayGroup<>();
 arrayGroup.addLast("风");
 arrayGroup.addLast("特");
 arrayGroup.addLast("烈");
 arrayGroup.add(1,"捷");
 arrayGroup.addFirst("张");
 System.out.println(arrayGroup);
 //ArrayGroup:size =5,capacity=10
 //[张, 风, 捷, 特, 烈]

@Override
public T get(int index) {
    if (index < 0 || index >= size) {
        throw new IllegalArgumentException("Get failed! Make sure index < 0 || index > size");
    }
    return datas[index];
}

 @Override
 public int[] getIndex(T el) {
     //临时数组
     int[] tempArray = new int[size];
     //重复个数
     int count = 0;
     //遍历集合,获取该元素重复个数，及位置数组
     for (int i = 0; i < size; i++) {
         if (datas[i].equals(el)) {
             tempArray[count] = i;
             count++;
         }
     }
     //将临时数组压缩
     int[] indexArray = new int[count];
     for (int i = 0; i < count; i++) {
         indexArray[i] = tempArray[i];
     }
     return indexArray;
 }

 @Override
 public T set(int index, T el) {
     if (index < 0 || index >= size) {
         throw new IllegalArgumentException("Set failed! Make sure index < 0 || index > size");
     }
     T oldEl = get(index);
     datas[index] = el;
     return oldEl;
 }

@Override
public T remove(int index) {
    if (index < 0 || index >= size) {
        throw new IllegalArgumentException("Remove failed! Make sure index < 0 || index > size");
    }
    T temp = get(index);
    //从删除元素索引的下一位开始到结尾，依次左移
    for (int i = index + 1; i < size; i++) {
        datas[i - 1] = datas[i];
    }
    size--;
    //置空--游荡的对象
    datas[size] = null;
    return temp;
}

@Override
public void clear() {
    for (int i = size-1; i <= 0; i--) {
        remove(i);
    }
    size = 0;
}

@Override
public Group<T> contact(int index, Group<T> group) {
    //从index处遍历本数组，将待插入数据一个一个插入
    for (int i = index; i < index+group.size(); i++) {
        add(i+1, group.get(i-index));
    }
    return this;
}

    private static void otherTest(ArrayGroup<String> arrayGroup) {
        arrayGroup.addLast("a");
        arrayGroup.addLast("a");
        arrayGroup.addLast("b");
        arrayGroup.addLast("c");
        arrayGroup.addLast("f");
        arrayGroup.addLast("a");
        arrayGroup.addLast("e");
        arrayGroup.addLast("d");

        System.out.println(arrayGroup);
        //ArrayGroup:size =8,capacity=10
        //[a, a, b, c, f, a, e, d]

        //定点删除操作
        String remove = arrayGroup.remove(3);
        System.out.println(remove);//c
        System.out.println(arrayGroup);
        //ArrayGroup:size =7,capacity=10
        //[a, a, b, f, a, e, d]

        //定元素删除
        int a = arrayGroup.removeEl("a");
        System.out.println(a);//0
        System.out.println(arrayGroup);
        //ArrayGroup:size =6,capacity=10
        //[a, b, f, a, e, d]

        //定元素全删除
        boolean ok = arrayGroup.removeEls("a");
        System.out.println(ok);//true
        System.out.println(arrayGroup);
        //ArrayGroup:size =4,capacity=10
        //[b, f, e, d]

        //定点修改
        String toly = arrayGroup.set(3, "toly");
        System.out.println(toly);//d
        System.out.println(arrayGroup);
        //ArrayGroup:size =4,capacity=10
        //[b, f, e, toly]

        //是否存在元素
        boolean contains = arrayGroup.contains("b");
        System.out.println(contains);//true

        //定点插入集合
        ArrayGroup<String> arrayGroup2 = new ArrayGroup<>();
        arrayGroup2.addLast("1");
        arrayGroup2.addLast("2");
        arrayGroup.contact(2,arrayGroup2);
        System.out.println(arrayGroup);
        //ArrayGroup:size =6,capacity=10
        //[b, f, e, 1, 2, toly]

        //末尾插入集合
        arrayGroup.contact(arrayGroup2);
        System.out.println(arrayGroup);
        //ArrayGroup:size =8,capacity=10
        //[b, f, e, 1, 2, toly, 1, 2]
        
        //清空
        arrayGroup.clear();
        System.out.println(arrayGroup);
        //ArrayGroup:size =0,capacity=10
        //[]
    }

/**
 * 扩容 
 *
 * @param newCapacity 新容量
 */
private void grow(int newCapacity) {
    T[] newData = (T[]) new Object[newCapacity];
    for (int i = 0; i < size; i++) {
        newData[i] = datas[i];
    }
    datas = newData;
}

 @Override
 public void add(int index, T el) {
     if (size == datas.length) {
         grow((int) (GROW_RATE * datas.length));
     }

 //缩容
 if (size == datas.length /4 && datas.length/2 !=0){
     grow(datas.length /2);
 }