Complete day 8

src/main/java/com/mattrixwv/adventOfCode24/ProblemSelector.java

@@ -13,6 +13,8 @@ import com.mattrixwv.adventOfCode24.days.Problem11;
 import com.mattrixwv.adventOfCode24.days.Problem12;
 import com.mattrixwv.adventOfCode24.days.Problem13;
 import com.mattrixwv.adventOfCode24.days.Problem14;
+import com.mattrixwv.adventOfCode24.days.Problem15;
+import com.mattrixwv.adventOfCode24.days.Problem16;
 import com.mattrixwv.adventOfCode24.days.Problem2;
 import com.mattrixwv.adventOfCode24.days.Problem3;
 import com.mattrixwv.adventOfCode24.days.Problem4;
@@ -28,7 +30,7 @@ public class ProblemSelector{
 	//Holds the valid problem numbers
 	protected static final List<Integer> PROBLEM_NUMBERS = List.of(
 		 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,
-		10, 11, 12, 13, 14
+		10, 11, 12, 13, 14, 15, 16
 	);
 
 
@@ -55,6 +57,8 @@ public class ProblemSelector{
 			case 12 : day = new Problem12(); break;
 			case 13 : day = new Problem13(); break;
 			case 14 : day = new Problem14(); break;
+			case 15 : day = new Problem15(); break;
+			case 16 : day = new Problem16(); break;
 			default: throw new InvalidParameterException();
 		}
 		return day;

src/main/java/com/mattrixwv/adventOfCode24/days/Problem15.java

@@ -0,0 +1,123 @@
+package com.mattrixwv.adventOfCode24.days;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.Set;
+
+import com.mattrixwv.Stopwatch;
+import com.mattrixwv.Triple;
+
+
+public class Problem15 extends Problem{
+	private static final String inputFileName = "days/Problem15.txt";
+	private List<String> map;
+	private Set<Triple<Integer, Integer, Character>> antiNodes;
+
+
+	public Problem15(){
+		super();
+		description = "Find the number of unique anti-nodes in the bounds of the map.";
+		result = "Unresolved";
+	}
+
+	public String runSolution(){
+		Stopwatch timer = new Stopwatch();
+		timer.start();
+
+
+		//Read the file
+		map = new ArrayList<>();
+		try(Scanner scanner = new Scanner(this.getClass().getClassLoader().getResourceAsStream(inputFileName))){
+			scanner.useDelimiter("\n");
+			while(scanner.hasNext()){
+				String inputLine = scanner.next();
+				if(inputLine.isBlank()){
+					continue;
+				}
+				else{
+					map.add(inputLine);
+				}
+			}
+		}
+
+
+		findAntiNodes();
+
+
+		//Save the results
+		timer.stop();
+		result = "There are " + antiNodes.size() + " anti-nodes in the boundaries of the map.\nIt took " + timer.toString() + " to run this algorithm.";
+		return result;
+	}
+
+	private void findAntiNodes(){
+		antiNodes = new HashSet<>();
+		//Step through the map and find all nodes
+		Map<Character, List<Triple<Integer, Integer, Character>>> nodes = new HashMap<>();
+		nodes.put('.', new ArrayList<>());
+		for(String mapRow : map){
+			for(char ch : mapRow.toCharArray()){
+				if(!nodes.containsKey(ch)){
+					nodes.put(ch, findMatchingElements(ch));
+				}
+			}
+		}
+
+		//Step through the list of nodes and find all anti-nodes
+		for(Character key : nodes.keySet()){
+			List<Triple<Integer, Integer, Character>> nodeList = nodes.get(key);
+			for(int nodeLoc1 = 0;nodeLoc1 < nodeList.size();++nodeLoc1){
+				for(int nodeLoc2 = nodeLoc1 + 1;nodeLoc2 < nodeList.size();++nodeLoc2){
+					Triple<Integer, Integer, Character> node1 = nodeList.get(nodeLoc1);
+					Triple<Integer, Integer, Character> node2 = nodeList.get(nodeLoc2);
+					int rowDifference = node1.getA() - node2.getA();
+					int colDifference = node1.getB() - node2.getB();
+					//Forwards node
+					int antiNode1Row = node1.getA() + rowDifference;
+					int antiNode1Col = node1.getB() + colDifference;
+					if(isInBounds(antiNode1Row, antiNode1Col)){
+						antiNodes.add(new Triple<>(antiNode1Row, antiNode1Col, 'A'));
+					}
+					//Backwards node
+					int antiNode2Row = node2.getA() - rowDifference;
+					int antiNode2Col = node2.getB() - colDifference;
+					if(isInBounds(antiNode2Row, antiNode2Col)){
+						antiNodes.add(new Triple<>(antiNode2Row, antiNode2Col, 'A'));
+					}
+				}
+			}
+		}
+	}
+
+	private List<Triple<Integer, Integer, Character>> findMatchingElements(char element){
+		List<Triple<Integer, Integer, Character>> elements = new ArrayList<>();
+		//Step through each row in the map searching for the given character
+		for(int row = 0;row < map.size();++row){
+			char[] mapRow = map.get(row).toCharArray();
+			for(int col = 0;col < mapRow.length;++col){
+				if(mapRow[col] == element){
+					elements.add(new Triple<Integer, Integer, Character>(row, col, element));
+				}
+			}
+		}
+		return elements;
+	}
+
+	private boolean isInBounds(int row, int col){
+		return
+			(row >= 0) && (row < map.size()) &&
+			(col >= 0) && (col < map.get(row).length());
+	}
+}
+
+
+/*
+Find the number of unique anti-nodes in the bounds of the map.
+There are 409 anti-nodes in the boundaries of the map.
+It took 6.557 milliseconds to run this algorithm.
+*/

src/main/java/com/mattrixwv/adventOfCode24/days/Problem16.java

@@ -0,0 +1,130 @@
+package com.mattrixwv.adventOfCode24.days;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.Set;
+
+import com.mattrixwv.Stopwatch;
+import com.mattrixwv.Triple;
+
+
+public class Problem16 extends Problem{
+	private static final String inputFileName = "days/Problem15.txt";
+	private List<String> map;
+	private Set<Triple<Integer, Integer, Character>> antiNodes;
+
+
+	public Problem16(){
+		super();
+		description = "Find the number of unique anti-nodes in the bounds of the map.";
+		result = "Unresolved";
+	}
+
+	public String runSolution(){
+		Stopwatch timer = new Stopwatch();
+		timer.start();
+
+
+		//Read the file
+		map = new ArrayList<>();
+		try(Scanner scanner = new Scanner(this.getClass().getClassLoader().getResourceAsStream(inputFileName))){
+			scanner.useDelimiter("\n");
+			while(scanner.hasNext()){
+				String inputLine = scanner.next();
+				if(inputLine.isBlank()){
+					continue;
+				}
+				else{
+					map.add(inputLine);
+				}
+			}
+		}
+
+		findAntiNodes();
+
+
+		//Save the results
+		timer.stop();
+		result = "There are " + antiNodes.size() + " anti-nodes in the boundaries of the map.\nIt took " + timer.toString() + " to run this algorithm.";
+		return result;
+	}
+
+	private void findAntiNodes(){
+		antiNodes = new HashSet<>();
+		//Step through the map and find all nodes
+		Map<Character, List<Triple<Integer, Integer, Character>>> nodes = new HashMap<>();
+		nodes.put('.', new ArrayList<>());
+		for(String mapRow : map){
+			for(char ch : mapRow.toCharArray()){
+				if(!nodes.containsKey(ch)){
+					nodes.put(ch, findMatchingElements(ch));
+				}
+			}
+		}
+
+		//Step through the list of nodes and find all anti-nodes
+		for(Character key : nodes.keySet()){
+			List<Triple<Integer, Integer, Character>> nodeList = nodes.get(key);
+			for(int nodeLoc1 = 0;nodeLoc1 < nodeList.size();++nodeLoc1){
+				for(int nodeLoc2 = nodeLoc1 + 1;nodeLoc2 < nodeList.size();++nodeLoc2){
+					Triple<Integer, Integer, Character> node1 = nodeList.get(nodeLoc1);
+					Triple<Integer, Integer, Character> node2 = nodeList.get(nodeLoc2);
+					//Since there are at least 2 elements add each as a resonance point
+					antiNodes.add(new Triple<>(node1.getA(), node1.getB(), 'A'));
+					antiNodes.add(new Triple<>(node2.getA(), node2.getB(), 'A'));
+
+					int rowDifference = node1.getA() - node2.getA();
+					int colDifference = node1.getB() - node2.getB();
+					//Forwards node
+					int antiNode1Row = node1.getA() + rowDifference;
+					int antiNode1Col = node1.getB() + colDifference;
+					while(isInBounds(antiNode1Row, antiNode1Col)){
+						antiNodes.add(new Triple<>(antiNode1Row, antiNode1Col, 'A'));
+						antiNode1Row += rowDifference;
+						antiNode1Col += colDifference;
+					}
+					//Backwards node
+					int antiNode2Row = node2.getA() - rowDifference;
+					int antiNode2Col = node2.getB() - colDifference;
+					while(isInBounds(antiNode2Row, antiNode2Col)){
+						antiNodes.add(new Triple<>(antiNode2Row, antiNode2Col, 'A'));
+						antiNode2Row -= rowDifference;
+						antiNode2Col -= colDifference;
+					}
+				}
+			}
+		}
+	}
+
+	private List<Triple<Integer, Integer, Character>> findMatchingElements(char element){
+		List<Triple<Integer, Integer, Character>> elements = new ArrayList<>();
+		//Step through each row in the map searching for the given character
+		for(int row = 0;row < map.size();++row){
+			char[] mapRow = map.get(row).toCharArray();
+			for(int col = 0;col < mapRow.length;++col){
+				if(mapRow[col] == element){
+					elements.add(new Triple<Integer, Integer, Character>(row, col, element));
+				}
+			}
+		}
+		return elements;
+	}
+
+	private boolean isInBounds(int row, int col){
+		return
+			(row >= 0) && (row < map.size()) &&
+			(col >= 0) && (col < map.get(row).length());
+	}
+}
+
+
+/*
+Find the number of unique anti-nodes in the bounds of the map.
+There are 1308 anti-nodes in the boundaries of the map.
+It took 8.836 milliseconds to run this algorithm.
+*/

src/main/resources/days/Problem15.txt

@@ -0,0 +1,50 @@
+........0.......................c.................
+........a.........................................
+.......0........................................r.
+.....W............................................
+..............Z..F.......................c........
+..F....a.....................c.......Lr....5......
+............................v.......L5............
+..................0.....v............r...E........
+...a..........................p..E..5...7L.m...Z..
+......j..0............z.....p.........E...........
+...j...S...W.7................J........4..........
+......W........X...............................4..
+W..........................p................M.....
+i........Z....................L.............U.....
+.....z....j..X..............................b....M
+........................Z......m..................
+....f.........X........J................4......H..
+y..................p............X.JvmR.U..........
+..................................................
+................................4.................
+.........N........................U...............
+........u...q.......5....J..7.................M...
+.y..i.F...z..........................9x.....A.....
+...i.....2...zw....Y.........................M....
+............Bu.................I...........U......
+..f.....2.......k...........b.........I.......x...
+.f............................................G...
+.O...o.......f...............7.t..Q.G.............
+a.....N....i2.........g..o...RI........G..........
+......oy...q..........N..H........sQ..............
+....y..2............K........b........9...m.......
+.......w...............b....Y........G.......A....
+......uO.w............q.k..Y.....v.............A..
+...u...K....O..............I......................
+o.O.........w.......Y.........R.Q..............T..
+......................t...3........k...x...C9.....
+.............q........3..6......t............Q.x..
+V......................N..............S...........
+..............6....K...............1...n..P.......
+......8..........................T....H.........1.
+..................s....t.....3....H.......n.......
+......K.g6...B...........h..T..l.....P.....9......
+..................l....k..T....h............1....e
+............6.........l.......h.....Pe..C.........
+...........s.V....................e..........C....
+.....8...V.......s.g...........n......e...........
+..V......B.g...........l.8........................
+......B.................R..3...............1.....S
+........................h...................S...CP
+..................................................