Complete day 3

src/main/java/com/mattrixwv/adventOfCode24/days/Problem5.java

@@ -0,0 +1,70 @@
+package com.mattrixwv.adventOfCode24.days;
+
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Scanner;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import com.mattrixwv.Stopwatch;
+
+
+public class Problem5 extends Problem{
+	private static final String inputFileName = "days/Problem5.txt";
+
+
+	public Problem5(){
+		super();
+		description = "Find the non-corrupted multiplication instructions that are allowed to run.";
+		result = "Unresolved";
+	}
+
+	public String runSolution(){
+		Stopwatch timer = new Stopwatch();
+		timer.start();
+
+		int sum = 0;
+		StringBuilder fileInput = new StringBuilder();
+
+
+		//Read the file
+		try(Scanner scanner = new Scanner(this.getClass().getClassLoader().getResourceAsStream(inputFileName))){
+			while(scanner.hasNext()){
+				fileInput.append(scanner.next());
+			}
+		}
+
+		//Pull out the valid references from the file
+		Pattern functionPattern = Pattern.compile("mul\\(\\d{1,3},\\d{1,3}\\)");
+		Matcher functionMatcher = functionPattern.matcher(fileInput.toString());
+		List<String> functions = new ArrayList<>();
+		while(functionMatcher.find()){
+			functions.add(functionMatcher.group());
+		}
+		StringBuilder functionString = new StringBuilder();
+		functions.forEach(func -> functionString.append(func));
+
+		//Perform the required multiplication
+		Pattern digitPattern = Pattern.compile("\\d{1,3}");
+		Matcher digitMatcher = digitPattern.matcher(functionString.toString());
+		while(digitMatcher.find()){
+			int num1 = Integer.parseInt(digitMatcher.group());
+			digitMatcher.find();
+			int num2 = Integer.parseInt(digitMatcher.group());
+			sum += (num1 * num2);
+		}
+
+
+		//Save the results
+		timer.stop();
+		result = "The sum of the non-corrupted multiplication instructions is " + sum + ".\nIt took " + timer.toString() + " to run the algorithm.";
+		return result;
+	}
+}
+
+/*
+Find the non-corrupted multiplication instructions that are allowed to run
+The sum of the non-corrupted multiplication instructions is 168539636.
+It took 13.816 milliseconds to run the algorithm.
+*/