JasonChang

摘要： The Abstract Factory Pattern provides an interface for creating families of related or dependent objects without specifying their concrete classes.implementation 阅读全文

摘要： The Factory Method Pattern defines an interface for creating an object, but lets subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses.implementation 阅读全文

摘要： The Decorator Pattern attaches additional responsibilities to an object dynamically. Decorators provide a flexible alternative to subclassing for extendingfunctionality.implementation 阅读全文

摘要： The Observer Pattern defines a one-to-many dependency between objects so that when one object changes state, all of its dependents are notified and updated automatically. Observer Pattern = Publisher + Subcribersimplemenation: 阅读全文

摘要： 1 /** 2 * Definition for singly-linked list with a random pointer. 3 * class RandomListNode { 4 * int label; 5 * RandomListNode next, random; 6 * RandomListNode(int x) { this.label = x; } 7 * }; 8 */ 9 public class Solution {10 public RandomListNode copyRandomList(RandomListN... 阅读全文

摘要： 1 public class Solution { 2 public int[] twoSum(int[] numbers, int target) { 3 HashMap visited = new HashMap(); 4 int[] result = new int[2]; 5 for(int i = 0; i < numbers.length; i++){ 6 int tmp = target - numbers[i]; 7 if(visited.containsKey(tmp))... 阅读全文

摘要： 1 public class Solution { 2 public ListNode addTwoNumbers(ListNode l1, ListNode l2) { 3 if(l1 == null) 4 return l2; 5 if(l2 == null) 6 return l1; 7 ListNode fakehead = new ListNode(0); 8 ListNode pre = fakehead; 9 int carry = 0;10 ... 阅读全文

摘要： 1 public class Solution { 2 public int longestConsecutive(int[] num) { 3 // IMPORTANT: Please reset any member data you declared, as 4 // the same Solution instance will be reused for each test case. 5 int len = num.length; 6 if(len table = new HashMap(); 9 ... 阅读全文

摘要： String equals() == 1 public class Solution { 2 public int evalRPN(String[] tokens) { 3 // IMPORTANT: Please reset any member data you declared, as 4 // the same Solution instance will be reused for each test case. 5 Stack stack = new Stack(); 6 if(tokens == null |... 阅读全文

摘要： 1 /** 2 * Definition for binary tree 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */10 public class Solution {11 public int minDepth(TreeNode root) {12 // IMPORTANT: Please reset any memb... 阅读全文