class Solution {
    public double maxAverageRatio(int[][] classes, int extraStudents) {
        PriorityQueue<double[]> maxHeap = new PriorityQueue<>(
            Comparator.comparingDouble(o -> -o[0])
        ); // Max heap compared by first value in decreasing order.
        for (int[] c : classes) {
            double a = c[0], b = c[1];
            maxHeap.offer(new double[]{profit(a, b), a, b});
        }
        while (extraStudents > 0) {
            double[] top = maxHeap.poll();
            double a = top[1], b = top[2];
            maxHeap.offer(new double[]{profit(a + 1, b + 1), a + 1, b + 1});
            extraStudents--;
        }
        double ans = 0.0;
        while (!maxHeap.isEmpty()) {
            double[] top = maxHeap.poll();
            double a = top[1], b = top[2];
            ans += a / b;
        }
        return ans / classes.length;
    }

    double profit(double a, double b) {
        return (a + 1) / (b + 1) - a / b;
    }
}