2303. Calculate Amount Paid in Taxes

class Solution {
    public double calculateTax(int[][] brackets, int income) {
        double res = 0.0;
        double lower = 0.0;
        for (int i = 0; i < brackets.length; i++) {
            double upper = brackets[i][0];
            if (income >= upper) {
                res += (upper - lower) * brackets[i][1] / 100.0;
                lower = upper;
            } else {
                res += (income - lower) * brackets[i][1] / 100.0;
                break; // !!
            }
        }
        return res;
    }
}