SkylineProblem.java move Others Directory and Refactoring other files

Author: sangjun2

Data Structures/Graphs/BFS.java

@@ -6,7 +6,7 @@
  * @author Unknown
  *
  */
-public class bfs{
+public class BFS{
 
 	/**
 	 * The BFS implemented in code to use.

Data Structures/Graphs/DFS.java

@@ -7,7 +7,7 @@
  *
  */
 
-public class dfs{
+public class DFS{
 
 	/**
 	 * Implementation in code of a DFS

Data Structures/Graphs/PrimMST.java

@@ -100,7 +100,7 @@ public static void main (String[] args)
         | /      \ |
         (3)-------(4)
              9          */
-        MST t = new MST();
+        PrimMST t = new PrimMST();
         int graph[][] = new int[][] {{0, 2, 0, 6, 0},
                                     {2, 0, 3, 8, 5},
                                     {0, 3, 0, 0, 7},

Dynamic Programming/LevenshteinDistance.java

@@ -6,7 +6,7 @@
  *
  */
 
-public class Levenshtein_distance{
+public class LevenshteinDistance{
 	private static int minimum(int a, int b, int c){
 		if(a < b && a < c){
 			return a;

Others/SkylineProblem.java

@@ -0,0 +1,131 @@
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.Scanner;
+
+public class SkylineProblem {
+	Building[] building;
+	int count;
+	
+	public void run() {
+		Scanner sc = new Scanner(System.in);
+		
+		int num = sc.nextInt();
+		this.building = new Building[num];
+		
+		for(int i = 0; i < num; i++) {
+			String input = sc.next();
+			String[] data = input.split(",");
+			this.add(Integer.parseInt(data[0]), Integer.parseInt(data[1]), Integer.parseInt(data[2]));
+		}
+		this.print(this.findSkyline(0, num - 1));
+		
+		sc.close();
+	}
+	
+	public void add(int left, int height, int right) {
+		building[count++] = new Building(left, height, right);
+	}
+	
+	public void print(ArrayList<Skyline> skyline) {
+		Iterator<Skyline> it = skyline.iterator();
+		
+		while(it.hasNext()) {
+			Skyline temp = it.next();
+			System.out.print(temp.coordinates + "," + temp.height);
+			if(it.hasNext()) {
+				System.out.print(",");
+			}
+		}
+		
+	}
+	
+	public ArrayList<Skyline> findSkyline(int start, int end) {
+		if(start == end) {
+			ArrayList<Skyline> list = new ArrayList<>();
+			list.add(new Skyline(building[start].left, building[start].height));
+			list.add(new Skyline(building[end].right, 0));
+			
+			return list;
+		}
+		
+		int mid = (start + end) / 2;
+		
+		ArrayList<Skyline> sky1 = this.findSkyline(start, mid);
+		ArrayList<Skyline> sky2 = this.findSkyline(mid + 1, end);
+		
+		return this.mergeSkyline(sky1, sky2);
+	}
+	
+	public ArrayList<Skyline> mergeSkyline(ArrayList<Skyline> sky1, ArrayList<Skyline> sky2) {
+		int currentH1 = 0, currentH2 = 0;
+		ArrayList<Skyline> skyline = new ArrayList<>();
+		int maxH = 0;
+		
+		while(!sky1.isEmpty() && !sky2.isEmpty()) {
+			if(sky1.get(0).coordinates < sky2.get(0).coordinates) {
+				int currentX = sky1.get(0).coordinates;
+				currentH1 = sky1.get(0).height;
+				
+				if(currentH1 < currentH2) {
+					sky1.remove(0);
+					if(maxH != currentH2) skyline.add(new Skyline(currentX, currentH2));
+				} else {
+					maxH = currentH1;
+					sky1.remove(0);
+					skyline.add(new Skyline(currentX, currentH1));
+				}
+			} else {
+				int currentX = sky2.get(0).coordinates;
+				currentH2 = sky2.get(0).height;
+				
+				if(currentH2 < currentH1) {
+					sky2.remove(0);
+					if(maxH != currentH1) skyline.add(new Skyline(currentX, currentH1));
+				} else {
+					maxH = currentH2;
+					sky2.remove(0);
+					skyline.add(new Skyline(currentX, currentH2));
+				}
+			}
+		}
+
+		while(!sky1.isEmpty()) {
+			skyline.add(sky1.get(0));
+			sky1.remove(0);
+		}
+		
+		while(!sky2.isEmpty()) {
+			skyline.add(sky2.get(0));
+			sky2.remove(0);
+		}
+		
+		return skyline;
+	}
+	
+	public class Skyline {
+		public int coordinates;
+		public int height;
+		
+		public Skyline(int coordinates, int height) {
+			this.coordinates = coordinates;
+			this.height = height;
+		}
+	}
+	
+	public class Building {
+		public int left;
+		public int height;
+		public int right;
+		
+		public Building(int left, int height, int right) {
+			this.left = left;
+			this.height = height;
+			this.right = right;
+		}
+	}
+	
+	public static void main(String[] args) {
+		SkylineProblem skylineProblem = new SkylineProblem();
+		skylineProblem.run();
+	}
+}