src/courseSber/homework/hw3/task3/MyArrayList.java - master - eelamimi/SberJavaCourseBeginner

src/courseSber/homework/hw3/task3/MyArrayList.java
110 строк2 KB
glebka
task 3.3 complete
09 мар 2025, 23:42
09 мар 2025, 23:42dd54bf7
package courseSber.homework.hw3.task3;

import java.util.Arrays;
import java.util.Iterator;
import java.util.NoSuchElementException;

public class MyArrayList<S> implements Iterable<S>{
    private S[] arr;
    private int size;

    public MyArrayList() {
        this.arr = (S[]) new Object[1];
        this.size = 0;
    }

    public MyArrayList(S[] arr) {
        this.arr = arr;
        this.size = arr.length;
    }

    public int size() {
        return size;
    }

    public S get(int ind) {
        return arr[ind];
    }

    public void set(int ind, S el) {
        if (0 <= ind && ind < size) {
            arr[ind] = el;
        } else {
            throw new ArrayIndexOutOfBoundsException("Индекс выходит за пределы массива");
        }
    }

    public int add(S el) {
        if (size == arr.length) {
            S[] arrBuf = (S[]) new Object[arr.length + 1];
            System.arraycopy(arr, 0, arrBuf, 0, size);
            arr = arrBuf;
        }
        arr[size] = el;
        size++;
        return size - 1;
    }

    public int indexOf(S el) {
        for (int i = 0; i < size; i++) {
            if (arr[i].equals(el)) {
                return i;
            }
        }
        return -1;
    }

    public boolean contains(S el) {
        for (int i = 0; i < size; i++) {
            if (arr[i].equals(el)) {
                return true;
            }
        }
        return false;
    }

    public boolean remove(S el) {
        if (contains(el)) {
            return remove(indexOf(el));
        } else {
            return false;
        }
    }

    public boolean remove(int ind) {
        if (!(0 <= ind && ind < size)) {
            return false;
        }
        S[] arrBuf = (S[]) new Object[arr.length - 1];
        System.arraycopy(arr, 0, arrBuf, 0, ind);
        System.arraycopy(arr, ind + 1, arrBuf, ind, arr.length - ind - 1);
        arr = arrBuf;
        size--;
        return true;
    }

    @Override
    public String toString() {
        return "Массив: " + Arrays.toString(arr);
    }

    @Override
    public Iterator<S> iterator() {
        return new Iterator<>() {
            private int curInd = 0;

            @Override
            public boolean hasNext() {
                return curInd < size;
            }

            @Override
            public S next() {
                if (!hasNext()) {
                    throw new NoSuchElementException();
                }
                return arr[curInd++];
            }
        };
    }
}