package com.mattrixwv.adventOfCode24.days;


import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

import com.mattrixwv.Stopwatch;


public class Problem2 extends Problem{
	private static final String inputFileName = "days/Problem1.txt";


	public Problem2(){
		super();
		description = "Find the similarity score between the two columsn of numbers";
		result = "Unresolved";
	}


	@Override
	public String runSolution(){
		Stopwatch timer = new Stopwatch();
		timer.start();

		int totalSimilarityScore = 0;

		ArrayList<Integer> column1 = new ArrayList<>(1000);
		ArrayList<Integer> column2 = new ArrayList<>(1000);


		//Read elements from the file into memory
		try(Scanner scanner = new Scanner(this.getClass().getClassLoader().getResourceAsStream(inputFileName))){
			scanner.useDelimiter("\\s+");

			while(scanner.hasNext()){
				String token1 = scanner.next();
				String token2 = scanner.next();

				column1.add(Integer.parseInt(token1));
				column2.add(Integer.parseInt(token2));
			}
		}

		//Sort the two lists of ids
		Collections.sort(column1);
		Collections.sort(column2);

		//Get the similarity score of each elements and keep a running sum
		//The similarity score is the element in column 1 multiplied by the number of times it appears in column 2
		for(Integer num : column1){
			int count = count(num, column2);
			totalSimilarityScore += (num * count);
		}

		//Save the results
		timer.stop();
		result = "The similarity score between the two columns of numbers is " + totalSimilarityScore + ".\nIt took " + timer.toString() + " to run the algorithm.";

		return result;
	}

	//Get the number of times a number appears in the list
	private int count(int num, List<Integer> list){
		int cnt = 0;

		for(Integer n : list){
			if(n == num){
				++cnt;
			}
			if(n > num){
				break;
			}
		}

		return cnt;
	}
}

/*
Find the similarity score between the two columns of numbers
The similarity score between the two columns of numbers is 24316233.
It took 17.875 milliseconds to run the algorithm.
*/