java Double Map HashMap Integer Null

Complete the function, which calculates how much you need to tip based on the total amount of the bill and the service.
完成一个函数,基于总金额和服务水平评级,计算出你需要付出多少小费
You need to consider the following ratings:
你需要参照以下关于评级的比例:
Terrible: tip 0%
Poor: tip 5%
Good: tip 10%
Great: tip 15%
Excellent: tip 20%
The rating is case insensitive (so “great” = “GREAT”). If an unrecognised rating is received, then you need to return:
评级不区分大小写,如果接收到无法识别的评分,则需要返回:
“Rating not recognised” in Javascript, Python and Ruby…
…or null in Java
或 java里的 null
…or -1 in C#
Because you’re a nice person, you always round up the tip, regardless of the service.
由于你是个好人,不管服务如何,你通常会把小费凑整.

1:
public static Integer  method(double amount,String rating ){
         Double mid= count(rating);
         if(mid==null)return null;
         Double rate=amount * mid;
        return (int) Math.ceil(rate);
    }
    public static Double count(String rat)
    {
        switch (rat.toLowerCase()){
            case "terrible":
                return 0.0;
            case "poor":
                return 0.05;
            case "good":
                return 0.1;
            case "great":
                return 0.15;
            case "excellent":
                return 0.20;
            default:
                return null;
        }
    }
 2:
import java.util.*;
public class TipCalculator {
  public static Integer calculateTip(double amount, String rating) {
    switch(rating.toUpperCase()) {
    case "TERRIBLE": return 0;
    case "POOR": return (int)Math.ceil(0.05*amount);
    case "GOOD": return (int)Math.ceil(0.1*amount);
    case "GREAT": return (int)Math.ceil(0.15*amount);
    case "EXCELLENT": return (int)Math.ceil(0.2*amount);
    default: return null;
    }
   }
}
3:
 import java.util.Map;
 class MM{
	static Integer method(double amount,String rating){
	var tips=Map.of("terrible",0.0,"poor",0.05,"good",0.1,"great",0.15,"excellent",0.20);
	String rate=rating.toLowerCase();
	return tips.containsKey(rate)?(int)(Math.ceil(amount*tips.get(rate))):null;
}
}
4:
import java.util.*;

public class TipCalculator {
  
  private static Map<String, Double> ratings = Map.of("terrible", 0.0, "poor", 0.05, "good", 0.1, "great", 0.15, "excellent", 0.2);
  public static Integer calculateTip(double a, String r) {
    return ratings.get(r.toLowerCase()) == null ? null : (int)Math.ceil(a*ratings.get(r.toLowerCase()));
  }
}
5:
import java.util.HashMap;
import java.util.Map;

public class TipCalculator {

    private static Map<String, Integer> tips = new HashMap<>();

    static {
        tips.put("terrible", 0);
        tips.put("poor", 5);
        tips.put("good", 10);
        tips.put("great", 15);
        tips.put("excellent", 20);
    }

    public static Integer calculateTip(double amount, String rating) {
        Integer tipRating = tips.get(rating.toLowerCase());
        if (tipRating == null) return null;
        return (int) Math.ceil(tipRating * amount / 100);
    }
}

来源：CSDN

作者：fylive

链接：https://blog.csdn.net/qq_39472229/article/details/103802917