[Script]

public class DamageReduction {
    public static void main(String[] args) {
        double maxHp = 100;
        double currentHp = 80;
        double damage = 20;

        double reducedDamage = calculateReducedDamage(maxHp, currentHp, damage);
        System.out.println("Damage reduction effect after repair： " + reducedDamage);
    }

    public static double calculateReducedDamage(double maxHp, double currentHp, double damage) {
        double healthRatio = currentHp / maxHp;
        double reducedDamage = damage * (1 - healthRatio);
        return reducedDamage;
    }
}