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translation: Add Python and Java code for EN version (#1345)
* Add the intial translation of code of all the languages * test * revert * Remove * Add Python and Java code for EN version
This commit is contained in:
Yudong Jin
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/**
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* File: array.java
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* Created Time: 2022-11-25
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* Author: krahets (krahets@163.com)
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*/
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package chapter_array_and_linkedlist;
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import java.util.*;
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import java.util.concurrent.ThreadLocalRandom;
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public class array {
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/* Random access to elements */
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static int randomAccess(int[] nums) {
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// Randomly select a number in the interval [0, nums.length)
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int randomIndex = ThreadLocalRandom.current().nextInt(0, nums.length);
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// Retrieve and return a random element
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int randomNum = nums[randomIndex];
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return randomNum;
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}
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/* Extend array length */
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static int[] extend(int[] nums, int enlarge) {
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// Initialize an extended length array
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int[] res = new int[nums.length + enlarge];
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// Copy all elements from the original array to the new array
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for (int i = 0; i < nums.length; i++) {
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res[i] = nums[i];
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}
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// Return the new array after expansion
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return res;
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}
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/* Insert element num at `index` */
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static void insert(int[] nums, int num, int index) {
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// Move all elements after `index` one position backward
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for (int i = nums.length - 1; i > index; i--) {
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nums[i] = nums[i - 1];
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}
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// Assign num to the element at index
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nums[index] = num;
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}
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/* Remove the element at `index` */
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static void remove(int[] nums, int index) {
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// Move all elements after `index` one position forward
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for (int i = index; i < nums.length - 1; i++) {
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nums[i] = nums[i + 1];
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}
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}
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/* Traverse array */
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static void traverse(int[] nums) {
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int count = 0;
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// Traverse array by index
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for (int i = 0; i < nums.length; i++) {
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count += nums[i];
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}
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// Traverse array elements
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for (int num : nums) {
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count += num;
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}
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}
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/* Search for a specified element in the array */
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static int find(int[] nums, int target) {
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for (int i = 0; i < nums.length; i++) {
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if (nums[i] == target)
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return i;
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}
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return -1;
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}
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/* Driver Code */
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public static void main(String[] args) {
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/* Initialize an array */
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int[] arr = new int[5];
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System.out.println("Array arr = " + Arrays.toString(arr));
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int[] nums = { 1, 3, 2, 5, 4 };
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System.out.println("Array nums = " + Arrays.toString(nums));
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/* Random access */
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int randomNum = randomAccess(nums);
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System.out.println("Get a random element from nums = " + randomNum);
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/* Length extension */
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nums = extend(nums, 3);
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System.out.println("Extend the array length to 8, resulting in nums = " + Arrays.toString(nums));
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/* Insert element */
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insert(nums, 6, 3);
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System.out.println("Insert the number 6 at index 3, resulting in nums = " + Arrays.toString(nums));
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/* Remove element */
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remove(nums, 2);
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System.out.println("Remove the element at index 2, resulting in nums = " + Arrays.toString(nums));
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/* Traverse array */
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traverse(nums);
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/* Search for elements */
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int index = find(nums, 3);
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System.out.println("Find element 3 in nums, index = " + index);
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}
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}
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/**
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* File: linked_list.java
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* Created Time: 2022-11-25
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* Author: krahets (krahets@163.com)
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*/
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package chapter_array_and_linkedlist;
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import utils.*;
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public class linked_list {
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/* Insert node P after node n0 in the linked list */
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static void insert(ListNode n0, ListNode P) {
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ListNode n1 = n0.next;
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P.next = n1;
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n0.next = P;
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}
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/* Remove the first node after node n0 in the linked list */
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static void remove(ListNode n0) {
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if (n0.next == null)
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return;
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// n0 -> P -> n1
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ListNode P = n0.next;
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ListNode n1 = P.next;
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n0.next = n1;
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}
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/* Access the node at `index` in the linked list */
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static ListNode access(ListNode head, int index) {
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for (int i = 0; i < index; i++) {
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if (head == null)
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return null;
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head = head.next;
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}
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return head;
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}
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/* Search for the first node with value target in the linked list */
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static int find(ListNode head, int target) {
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int index = 0;
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while (head != null) {
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if (head.val == target)
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return index;
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head = head.next;
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index++;
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}
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return -1;
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}
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/* Driver Code */
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public static void main(String[] args) {
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/* Initialize linked list */
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// Initialize each node
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ListNode n0 = new ListNode(1);
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ListNode n1 = new ListNode(3);
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ListNode n2 = new ListNode(2);
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ListNode n3 = new ListNode(5);
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ListNode n4 = new ListNode(4);
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// Build references between nodes
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n0.next = n1;
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n1.next = n2;
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n2.next = n3;
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n3.next = n4;
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System.out.println("The initialized linked list is");
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PrintUtil.printLinkedList(n0);
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/* Insert node */
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insert(n0, new ListNode(0));
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System.out.println("Linked list after inserting the node is");
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PrintUtil.printLinkedList(n0);
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/* Remove node */
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remove(n0);
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System.out.println("Linked list after removing the node is");
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PrintUtil.printLinkedList(n0);
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/* Access node */
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ListNode node = access(n0, 3);
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System.out.println("The value of the node at index 3 in the linked list = " + node.val);
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/* Search node */
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int index = find(n0, 2);
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System.out.println("The index of the node with value 2 in the linked list = " + index);
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}
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}
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/**
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* File: list.java
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* Created Time: 2022-11-25
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* Author: krahets (krahets@163.com)
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*/
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package chapter_array_and_linkedlist;
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import java.util.*;
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public class list {
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public static void main(String[] args) {
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/* Initialize list */
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// The array's element type is Integer[], a wrapper class for int
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Integer[] numbers = new Integer[] { 1, 3, 2, 5, 4 };
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List<Integer> nums = new ArrayList<>(Arrays.asList(numbers));
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System.out.println("List nums = " + nums);
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/* Access element */
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int num = nums.get(1);
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System.out.println("Access the element at index 1, obtained num = " + num);
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/* Update element */
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nums.set(1, 0);
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System.out.println("Update the element at index 1 to 0, resulting in nums = " + nums);
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/* Clear list */
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nums.clear();
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System.out.println("After clearing the list, nums = " + nums);
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/* Add element at the end */
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nums.add(1);
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nums.add(3);
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nums.add(2);
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nums.add(5);
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nums.add(4);
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System.out.println("After adding elements, nums = " + nums);
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/* Insert element in the middle */
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nums.add(3, 6);
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System.out.println("Insert the number 6 at index 3, resulting in nums = " + nums);
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/* Remove element */
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nums.remove(3);
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System.out.println("Remove the element at index 3, resulting in nums = " + nums);
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/* Traverse the list by index */
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int count = 0;
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for (int i = 0; i < nums.size(); i++) {
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count += nums.get(i);
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}
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/* Traverse the list elements */
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for (int x : nums) {
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count += x;
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}
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/* Concatenate two lists */
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List<Integer> nums1 = new ArrayList<>(Arrays.asList(new Integer[] { 6, 8, 7, 10, 9 }));
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nums.addAll(nums1);
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System.out.println("Concatenate list nums1 to nums, resulting in nums = " + nums);
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/* Sort list */
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Collections.sort(nums);
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System.out.println("After sorting the list, nums = " + nums);
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}
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}
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/**
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* File: my_list.java
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* Created Time: 2022-11-25
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* Author: krahets (krahets@163.com)
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*/
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package chapter_array_and_linkedlist;
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import java.util.*;
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/* List class */
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class MyList {
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private int[] arr; // Array (stores list elements)
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private int capacity = 10; // List capacity
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private int size = 0; // List length (current number of elements)
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private int extendRatio = 2; // Multiple for each list expansion
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/* Constructor */
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public MyList() {
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arr = new int[capacity];
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}
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/* Get list length (current number of elements) */
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public int size() {
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return size;
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}
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/* Get list capacity */
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public int capacity() {
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return capacity;
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}
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/* Access element */
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public int get(int index) {
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// If the index is out of bounds, throw an exception, as below
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if (index < 0 || index >= size)
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throw new IndexOutOfBoundsException("Index out of bounds");
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return arr[index];
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}
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/* Update element */
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public void set(int index, int num) {
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if (index < 0 || index >= size)
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throw new IndexOutOfBoundsException("Index out of bounds");
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arr[index] = num;
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}
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/* Add element at the end */
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public void add(int num) {
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// When the number of elements exceeds capacity, trigger the expansion mechanism
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if (size == capacity())
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extendCapacity();
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arr[size] = num;
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// Update the number of elements
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size++;
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}
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/* Insert element in the middle */
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public void insert(int index, int num) {
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if (index < 0 || index >= size)
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throw new IndexOutOfBoundsException("Index out of bounds");
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// When the number of elements exceeds capacity, trigger the expansion mechanism
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if (size == capacity())
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extendCapacity();
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// Move all elements after `index` one position backward
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for (int j = size - 1; j >= index; j--) {
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arr[j + 1] = arr[j];
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}
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arr[index] = num;
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// Update the number of elements
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size++;
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}
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/* Remove element */
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public int remove(int index) {
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if (index < 0 || index >= size)
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throw new IndexOutOfBoundsException("Index out of bounds");
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int num = arr[index];
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// Move all elements after `index` one position forward
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for (int j = index; j < size - 1; j++) {
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arr[j] = arr[j + 1];
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}
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// Update the number of elements
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size--;
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// Return the removed element
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return num;
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}
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/* Extend list */
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public void extendCapacity() {
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// Create a new array with a length multiple of the original array by extendRatio, and copy the original array to the new array
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arr = Arrays.copyOf(arr, capacity() * extendRatio);
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// Update list capacity
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capacity = arr.length;
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}
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/* Convert the list to an array */
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public int[] toArray() {
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int size = size();
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// Only convert elements within valid length range
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int[] arr = new int[size];
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for (int i = 0; i < size; i++) {
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arr[i] = get(i);
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}
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return arr;
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}
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}
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public class my_list {
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/* Driver Code */
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public static void main(String[] args) {
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/* Initialize list */
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MyList nums = new MyList();
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/* Add element at the end */
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nums.add(1);
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nums.add(3);
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nums.add(2);
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nums.add(5);
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nums.add(4);
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System.out.println("List nums = " + Arrays.toString(nums.toArray()) +
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", capacity = " + nums.capacity() + ", length = " + nums.size());
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/* Insert element in the middle */
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nums.insert(3, 6);
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System.out.println("Insert the number 6 at index 3, resulting in nums = " + Arrays.toString(nums.toArray()));
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/* Remove element */
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nums.remove(3);
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System.out.println("Remove the element at index 3, resulting in nums = " + Arrays.toString(nums.toArray()));
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/* Access element */
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int num = nums.get(1);
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System.out.println("Access the element at index 1, obtained num = " + num);
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/* Update element */
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nums.set(1, 0);
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System.out.println("Update the element at index 1 to 0, resulting in nums = " + Arrays.toString(nums.toArray()));
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/* Test expansion mechanism */
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for (int i = 0; i < 10; i++) {
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// At i = 5, the list length will exceed the list capacity, triggering the expansion mechanism at this time
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nums.add(i);
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}
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System.out.println("After extending, list nums = " + Arrays.toString(nums.toArray()) +
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", capacity = " + nums.capacity() + ", length = " + nums.size());
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}
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}
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