Skyline Problem in Java

Skyline Problem In Java.


A city's skyline is the outer contour of the silhouette formed by all the buildings in that city when viewed from a distance. 
Now suppose you are given the locations and height of all the buildings as shown on a cityscape below. Write a program to output the skyline formed by these buildings collectively.

Lets simplify the problem statement and understand it correctly,
If there are many buildings in a area as shown in below picture, If same buildings is viewed from distance then what we can see is not all the buildings but the skyline that is borders of all buildings.

You can see skyline of buildings if viewed from a side and remove all sections that are not visible/overlapped.
All buildings have common base and every building is represented by 3 points(left, right, height)

‘left': is x coordinate of building left wall.

‘right': is x coordinate of building right wall
‘height': is height of building.


A skyline is a collection of rectangular strips. A rectangular strip is represented as a pair (left, height) where left is x coordinate of building left wall and height is height of building.

Lets understand what is the input and the expected output.

INPUT:
You are given a building coordinates as shown below,

int[][] skyscraper = { {2,9,10},  {3,6,15},  {5,12,12},  {13,16,10}, {15,17,5} };

OUTPUT:
Skyline Coordinates = { {2,10},  {3,15}, {6,12}, {12,0}, {13,10}, {16,5}, {17,0} }


Pass parameters to Quartz Job Scheduler

How to pass parameter to Quartz Scheduler Cron Trigger example in Java.


Integration of Quartz scheduler with Spring boot. Java Quartz scheduler cron expression example. Spring quartz scheduler postgresql database example.

Quartz Scheduler:  
  1. Quartz is a richly featured, open source Job scheduling library. 
  2. Quartz can be used to create simple or complex schedules for executing multiple jobs. 
  3. Using quartz library, job can be schedule which can be executed instantly or to be executed later point of time. 
  4. Quartz also accepts cron expression using which complex jobs can be scheduled like
    "Run job after every 5 minutes" or "Run job every week on monday at 3 PM" etc.
Spring boot:
  1. Spring boot is (Spring + Configuration) bundle which helps you to develop application faster.
  2. Spring boot take care of many configurations and helps developer focus on business. 
  3. It includes an embedded tomcat (or jetty) server.

Download file in Angular2

Download file using Angular2.

Download file in Angular2 from server.

Many a times we need to download file from server via HTTP call, In this post we will see how to download file in Angular2 using GET/POST request from server.
Example demonstrates downloading binary file using Angular2 and REST service.