Container With Most Water

Title: Container With Most Water Source: leetcode.com Given n non-negative integers a1, a2, …, an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such ...

Clone Graph

Title: Clone Graph Source: leetcode.com Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors. Nodes are labeled uniquely. Java solution Java /* https://leetcode.com/problems/clone-graph/ */ import java.util.HashMap; import java.util.List; import java.util.ArrayList; public class CloneGraph { public UndirectedGraphNode cloneGraph(UndirectedGraphNode node) { if(node==null) return null; HashMap<Integer, UndirectedGraphNode> visited = ...

Climbing Stairs

Title: Climbing Stairs Source: leetcode.com You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top? Java solution Java /* https://leetcode.com/problems/climbing-stairs/ */ import java.util.HashSet; class ClimbStairs { HashSet set = ...

Binary Tree Paths

Title: Binary Tree Paths Source: leetcode.com Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 12345    1 /   \2     3 \  5 All root-to-leaf paths are: ["1->2->5", "1->3"] 1 ["1->2->5", "1->3"] Java solution Java /* https://leetcode.com/problems/binary-tree-paths/ */ import java.util.List; import java.util.ArrayList; public ...

Add Digits

Title: Add Digits Source: leetcode.com Given a non-negative integer num, repeatedly add all its digits until the result has only one digit. For example: Given num = 38, the process is like: 3 + 8 = 11, 1 + 1 = 2. Since 2 has only one digit, return it. Follow up: Could you do ...

Bulls and Cows

Title: Bulls and Cows Source: leetcode.com You are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess what the number is. Each time your friend makes a guess, you provide a hint that indicates how many digits in said guess match your secret ...

Find maximal uni-directional path length for a Binary Tree 1

Continuing from our last post for a Generic Binary Tree implementation, we’ve come up with a solution to quite an interesting problem. We define a path in a binary tree to be a non-empty sequence of nodes that one can traverse by following the pointers in the nodes. A path only goes to the right ...

Implementing a Generic Binary Tree in Java 2

Implementing a Generic Binary Tree in Java
The following two classes demonstrate an implementation of the Generic Binary Tree data structure. The first class is BinaryTreeNode.java which acts as the node class for the tree, holding integer type data and two pointers for left and right child respectively of type same as the node class itself. The member fields are declared to ...

Data truncation: Incorrect datetime value: ” for column 2

While using Acitiviti API you might encounter this error which says something like this ### Error updating database. Cause: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Incorrect datetime value: ” for column ‘DEPLOY_TIME_’ at row 1### The error may involve org.activiti.engine.impl.persistence.entity.DeploymentEntity.insertDeployment-Inline### The error occurred while setting parameters### Cause: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Incorrect datetime value: ” for column ‘DEPLOY_TIME_’ at row ...

Add Two Integers without using Arithmetic Operators

Recently came across an interesting question of adding two numbers without using any of the arithmetic operators and thought of giving it a try. The first thought of solving the question was using bit-manipulation operations. The idea was to add the numbers bit-by-bit taking any carry forward (without actually adding them and instead using bit-wise ...