Big update: Adding all advent of codes to same repo

AdventOfCode2020/day8/day8.java

@@ -0,0 +1,109 @@
+import java.util.Scanner;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.ArrayList;
+
+class day8 {
+    
+    public static void main(String[] args) {
+        
+        File myFile = new File("input.txt");
+        try {
+            
+            Scanner in = new Scanner(myFile);
+            ArrayList<Instruction> instructions = new ArrayList<>();
+            
+            while (in.hasNext()) {
+                String[] split = in.nextLine().split(" ");
+                Instruction current = new Instruction(split[0], Integer.parseInt(split[1]), false);
+                instructions.add(current);
+            }
+            
+            boolean done = false;
+            int currentChangingInstruction = 0;
+            ArrayList<Integer> checked = new ArrayList<>();
+
+            while (!done) {
+                
+                while (instructions.get(currentChangingInstruction).instruction.equals("acc") || checked.contains(currentChangingInstruction)) {
+                    
+                    currentChangingInstruction++;
+                    
+                }
+
+                checked.add(currentChangingInstruction);
+                Instruction currentChange = instructions.get(currentChangingInstruction);
+                
+                if (currentChange.instruction.equals("jmp")) currentChange.instruction = "nop";
+                else currentChange.instruction = "jmp";
+                instructions.set(currentChangingInstruction, currentChange);
+                
+                for (Instruction i : instructions) System.out.println(i);
+                
+                int acc = 0;
+                int instructionIndex = 0;
+                Instruction currentInstruction = instructions.get(instructionIndex);
+                
+                while (currentInstruction.ran == false && done == false) {
+                    instructions.set(instructionIndex, new Instruction(currentInstruction.instruction, currentInstruction.arg, true));
+                    
+                    if (currentInstruction.instruction.equals("acc")) {
+                        acc += currentInstruction.arg;
+                        instructionIndex++;
+                    } else if (currentInstruction.instruction.equals("jmp")) {
+                        
+                        if (currentInstruction.arg + instructionIndex >= 0 && currentInstruction.arg + instructionIndex <= instructions.size()) {
+                            instructionIndex += currentInstruction.arg;
+                        } else {
+                            instructionIndex = instructions.size() % currentInstruction.arg;
+                        }
+                        
+                    } else {
+                        instructionIndex++;
+                    }
+                    
+                    if (instructionIndex == instructions.size()) {
+                        done = true;
+                        System.out.println("Acc: " + acc);
+                    } else {
+                        currentInstruction = instructions.get(instructionIndex);
+                    }
+
+                }
+
+                if (currentChange.instruction.equals("jmp")) currentChange.instruction = "nop";
+                else currentChange.instruction = "jmp";
+                instructions.set(currentChangingInstruction, currentChange);
+                
+                for (int i = 0; i < instructions.size(); i++) {
+                    Instruction changeRan = instructions.get(i);
+                    changeRan.ran = false;
+                    instructions.set(i, changeRan);
+                }
+                
+            }
+            
+        } catch (FileNotFoundException e) {
+            e.printStackTrace();
+        }
+        
+    }
+    
+}
+
+class Instruction {
+    public String instruction;
+    public int arg;
+    public boolean ran;
+    
+    public Instruction(String instruction, int arg, boolean ran) {
+        this.instruction = instruction;
+        this.arg = arg;
+        this.ran = ran;
+    }
+    
+    public String toString() {
+        return "Instruction : " + this.instruction + " | Arg: " + this.arg + " | Ran: " + this.ran;
+    }
+    
+}