記事のスペースが限られているため、いくつかの主要なデータ構造とアルゴリズムの実装例を示します。まず、いくつかのコアとなるデータ構造とアルゴリズムが紹介され、次に対応する Java コードの例が示されます。
public class DynamicArray<T> { private Object[] array; private int size; private int capacity; public DynamicArray() { capacity = 10; array = new Object[capacity]; size = 0; } public void add(T element) { if (size == capacity) { capacity *= 2; Object[] newArray = new Object[capacity]; System.arraycopy(array, 0, newArray, 0, size); array = newArray; } array[size++] = element; } public T get(int index) { if (index < 0 || index >= size) throw new IndexOutOfBoundsException(); return (T) array[index]; } public void remove(int index) { if (index < 0 || index >= size) throw new IndexOutOfBoundsException(); for (int i = index; i < size - 1; i++) { array[i] = array[i + 1]; } size--; } }
単一のリンク リストの実装
public class ListNode { int val; ListNode next; ListNode(int val) { this.val = val; } } public class LinkedList { private ListNode head; public void addAtHead(int val) { ListNode newHead = new ListNode(val); newHead.next = head; head = newHead; } public void addAtTail(int val) { if (head == null) { head = new ListNode(val); } else { ListNode current = head; while (current.next != null) { current = current.next; } current.next = new ListNode(val); } } public void deleteAtIndex(int index) { if (index == 0) { head = head.next; return; } int count = 0; ListNode current = head; ListNode prev = null; while (current != null && count < index) { prev = current; current = current.next; count++; } if (current != null) { prev.next = current.next; } } public ListNode get(int index) { ListNode current = head; int count = 0; while (current != null && count < index) { current = current.next; count++; } return current; } }
配列ベースのスタックの実装
public class ArrayStack { private int[] array; private int top; private int capacity; public ArrayStack(int capacity) { this.capacity = capacity; array = new int[capacity]; top = -1; } public void push(int value) { if (top == capacity - 1) throw new IllegalStateException("Stack is full"); array[++top] = value; } public int pop() { if (top == -1) throw new IllegalStateException("Stack is empty"); return array[top--]; } public int peek() { if (top == -1) throw new IllegalStateException("Stack is empty"); return array[top]; } public boolean isEmpty() { return top == -1; } }
配列ベースのキューの実装
public class ArrayQueue { private int[] array; private int front; private int rear; private int capacity; public ArrayQueue(int capacity) { this.capacity = capacity; array = new int[capacity]; front = 0; rear = -1; } public void enqueue(int value) { if (rear == capacity - 1) throw new IllegalStateException("Queue is full"); array[++rear] = value; } public int dequeue() { if (isEmpty()) throw new IllegalStateException("Queue is empty"); int value = array[front]; front++; return value; } public int peek() { if (isEmpty()) throw new IllegalStateException("Queue is empty"); return array[front]; } public boolean isEmpty() { return front > rear; } }
public class Sort { public static void bubbleSort(int[] array) { int length = array.length; for (int i = 0; i < length - 1; i++) { for (int j = 0; j < length - 1 - i; j++) { if (array[j] > array[j + 1]) { int temp = array[j]; array[j] = array[j + 1]; array[j + 1] = temp; } } } } public static void insertionSort(int[] array) { for (int i = 1; i < array.length; i++) { int current = array[i]; int j = i - 1; while (j >= 0 && array[j] > current) { array[j + 1] = array[j]; j--; } array[j + 1] = current; } } public static void selectionSort(int[] array) { for (int i = 0; i < array.length - 1; i++) { int minIndex = i; for (int j = i + 1; j < array.length; j++) { if (array[j] < array[minIndex]) { minIndex = j; } } int temp = array[i]; array[i] = array[minIndex]; array[minIndex] = temp; } } public static void quickSort(int[] array, int low, int high) { if (low < high) { int mid = partition(array, low, high); quickSort(array, low, mid - 1); quickSort(array, mid + 1, high); } } private static int partition(int[] array, int low, int high) { int pivot = array[high]; int i = low - 1; for (int j = low; j < high; j++) { if (array[j] < pivot) { i++; int temp = array[i]; array[i] = array[j]; array[j] = temp; } } int temp = array[i + 1]; array[i + 1] = array[high]; array[high] = temp; return i + 1; } }
以上がJAVAコアのデータ構造とアルゴリズムの実装の詳細内容です。詳細については、PHP 中国語 Web サイトの他の関連記事を参照してください。