For this puzzle we can make use of a max-heap to store the sum of calories carried by the elves in a descending order.
for part 1 of the problem we can peek the max-heap for the maximum calories
and for part 2 we can loop over the max-heap and find the sum of max-3 calories carried.
We can make use of a PriorityQueue in reverse order to make a max-head in java
import java.io.File;
import java.util.Collections;
import java.util.PriorityQueue;
import java.util.Scanner;
public class Day1 {
public static void main(String[] args) throws Exception {
String path = "D:\\projects\\AdventOfCode\\src\\input.txt";
File input = new File(path);
Scanner sc = new Scanner(input);
var pq = new PriorityQueue<Integer>(Collections.reverseOrder()); // max-heap
int calories = 0;
while (sc.hasNextLine()) {
String calorie = sc.nextLine();
// reset for new elf
if (calorie.equals("")) {
pq.offer(calories);
calories = 0;
continue;
}
calories += Integer.parseInt(calorie);
}
System.out.println("Result part 1 : " + pq.peek());
int res = 0;
for (int i = 0; i < 3; i++) {
res += pq.poll();
}
System.out.println("Result part 2 : " + res);
sc.close();
}
}
Oldest comments (0)