package com.aoc;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.List;
import java.util.Scanner;
import java.util.ArrayList;

class IntcodeCalculator {
    public int calculate(List <Integer> input, int param1, int param2) {
        List <Integer> intcode = new ArrayList <Integer> (input);

        intcode.set(1, param1);
        intcode.set(2, param2);

        for (int i = 0; i<intcode.size(); i += 4) {
            int opcode = intcode.get(i);
            if (opcode > 2 || opcode == 0) { break; }

            int x = intcode.get(intcode.get(i+1));
            int y = intcode.get(intcode.get(i+2));
            int pos = intcode.get(i+3);

            if (opcode == 1)      { intcode.set(pos, x + y); }
            else if (opcode == 2) { intcode.set(pos, x * y); }
        }   return intcode.get(0);
    }
}

class AOC1 {
    private static int param1 = 12;
    private static int param2 = 2;
    int solve(List <Integer> input) {
        IntcodeCalculator calculator = new IntcodeCalculator();
        return calculator.calculate(input, param1, param2);
    }
}
class AOC2 {
    private static int goal = 19690720;
    int solve(List <Integer> input) {
        IntcodeCalculator calculator = new IntcodeCalculator();
        int ans = -1;
        for (int param1=0; param1<100; ++param1) {
            for (int param2 = 0; param2 < 100; ++param2) {
                if (calculator.calculate(input, param1, param2) == goal) {
                    ans = param1 * 100 + param2;
                    break;
                }
            }
        }   return ans;
    }
}

class AOC2_2 {  // thanks reddit for the idea <3 u/aoc_anon
    private static int goal = 19690720;
    int solve(List <Integer> input) {
        IntcodeCalculator calculator = new IntcodeCalculator();
        int ans = -1;

        //  if param1 is a, param2 is b, the answer should be something like:
        //  x*a + y*b + z
        //  3 unknowns => 3 eq needed
        //  a = 0, b = 0: z
        //  a = 1, b = 0: x+z
        //  a = 0, b = 1: y+z

        int z = calculator.calculate(input, 0, 0);
        int x = calculator.calculate(input, 1, 0) - z;
        int y = calculator.calculate(input, 0, 1) - z;

        //  we need x*a + y*b + z == answer

        for (int a = 0; a <= 99; ++a) {
            int rem = goal - x*a - z;
            if (rem%y == 0) {
                int b = rem/y;
                if (b >= 0 && b <= 99) {
                    ans = a*100 + b;
                    break;
                }
            }
        }

        return ans;
    }
}

public class Main {
    private static List <Integer> parseInput() {
        List <Integer> answer = new ArrayList <Integer> ();

        try {
            Scanner scanner = new Scanner(new File("input.txt"));
            if (scanner.hasNextLine()) {
                String input = scanner.nextLine();
                for (String num : input.split(",")) {
                    answer.add(Integer.parseInt(num));
                }
            }
            else System.out.println("File data line missing!");
        }   catch (FileNotFoundException e) {
            System.out.println("File missing!");
        }

        return answer;
    }

    public static void main(String[] args) {
        AOC1 solver  = new AOC1();
        AOC2_2 solver2 = new AOC2_2();
        System.out.println(solver.solve(parseInput()));
        System.out.println(solver2.solve(parseInput()));
    }
}