chrynan This question was written poorly. Leave out the explanation to what annotations are; this is a test not a lesson. The whole code should have been written by the user and not just highlighted lines. And one should not have to infer from the sample input and ouput what certain values are (budgetLimit - 100 for senior and 50 for junior).
CMDodyAsked to answer [deleted]chrynan You obviously don't understand my comment. I did not say I was incapable of solving the question. In fact I have solved the question. I was merely stating that the question is written poorly (as are much of the questions on this site) and should be considered for refactoring.
CondrarAsked to answer Annotations are a overly complex, unclear part of Java (these words is not for those people who learn by heart in whole parts of the text without dissection). This complexity makes the annotation part of Java is overly unpleasant in learning. The conditions of this challenge are good: 1) simple and clear explanation in beginning, 2) most of the program written (this is good: more tutoring and less suffering). But I have been some suffering from uncertainty of the conditions in the values of budgetLimit too, chrynan: this is a good subchallenge, but lacks a little clarification: "I offer to guess about the values for budgetLimit from the problem statement."
_hemantgangwar Thanks...for clearing my doubt
anilkay [deleted]
marshallaf The instructions should be more clear that you also cannot add any lines to the code. All edits by the user must be within the marked lines (lines 70, 74, 81, 104, 106). Otherwise, the code won't pass, even if it outputs correctly.
gregoryeg thank you! i was banging my head against the wall trying to figure out why it kept failing with the correct result.
chris_ollenburg1 Yeah this is frustrating. Also it goes against standard code formatting practices for java.
tao_zhang The description is so bad, no where to find why senior should have 100 and junior should have 50 as limits. But these values somehow work. Solution below passes all testcases.
import java.lang.annotation.*; import java.lang.reflect.*; import java.util.*; @Target(ElementType.METHOD) @Retention(RetentionPolicy.RUNTIME) @interface FamilyBudget { String userRole() default "GUEST"; int budgetLimit() default 0; } class FamilyMember { @FamilyBudget(userRole = "SENIOR", budgetLimit = 100) public void seniorMember(int budget, int moneySpend) { System.out.println("Senior Member"); System.out.println("Spend: " + moneySpend); System.out.println("Budget Left: " + (budget - moneySpend)); } @FamilyBudget(userRole = "JUNIOR", budgetLimit = 50) public void juniorUser(int budget, int moneySpend) { System.out.println("Junior Member"); System.out.println("Spend: " + moneySpend); System.out.println("Budget Left: " + (budget - moneySpend)); } } public class Solution { public static void main(String[] args) { Scanner in = new Scanner(System.in); int testCases = Integer.parseInt(in.nextLine()); while (testCases > 0) { String role = in.next(); int spend = in.nextInt(); try { Class annotatedClass = FamilyMember.class; Method[] methods = annotatedClass.getMethods(); for (Method method : methods) { if (method.isAnnotationPresent(FamilyBudget.class)) { FamilyBudget family = method .getAnnotation(FamilyBudget.class); String userRole = family.userRole(); int budgetLimit = family.budgetLimit(); if (userRole.equals(role)) { if(budgetLimit >= spend){ method.invoke(FamilyMember.class.newInstance(), budgetLimit, spend); }else{ System.out.println("Budget Limit Over"); } } } } } catch (Exception e) { e.printStackTrace(); } testCases--; } } }
senthilrameshjv Although, I read tutorials and implemented the code, I dont know how it works. I mean, the family by default doesn't have senior or junior user. Which means, the familymember class don't know which method to invoke, when two parameters are passed.
I dont see any line that sets the userRole in the class as SENIOR or JUNIOR. I see the below line.
String userRole = family.userRole(); int budgetLimit = family.budgetLimit();This is infact, setting userRole from family. the default in family is guest, so it should set userRole as Guest which will never be equal to the inputs passed.
Am I understanding something different?
se_anilp basically you need to pass value inside annotation. e.g @FamilyBudget(userRole = "SENIOR", budgetLimit = 100)
shrutika_kapse44 How can we figure out that budget limit is 50&100. Nowhere it is mentioned.
Ayzhin You just had to guess from the test case they provided. The challenge was poorly written.
davidsgale The code loops through all of the methods in the FamilyMember class (seniorMember(...) and juniorUser(...)) for each test. For each method, it gets the annotations and checks to see if it's a valid method to call for the current role; if it is, it calls it with the method.invoke(...) line.
In other words, this is very obviously tutorial code, not something you would (I hope!) write in the real world. It's not going to be very performant; it would perform weirdly if there were multiple methods for the same role; and if the methods have different footprints, it throws an "IllegalArgumentException" at run (not compile) time.
This test shows you how annotations can be used, but not how they should be.
MrCurious Ya so true !! I was also get confused!! but finally found ;)
gridkid491 The values of 100 and 50 can be found by reverse engineering it (look at the input and output, you will see that the initial budget must be so). In addition, my test cases appear to fail even when the input/output matches exactly. They do not mention how to set the cardinality of the userRole, a.k.a. |userRole|.
yadavsaloni2018 Very poorly framed question and test cases. Note 1- only if you edit in the exact place will your test cases pass. Otherwise even if "expected output" and "your output" matches word by word, it fails the test cases. Note 2- its onto us to figure out from the example that for "juniors" the limit is 50 and 100 for "seniors". Note 3- 0 remaining out of the budget is considered "budget limit crossed" condition. That is an open interpretation. but on submission, your test case would fail if remaingin=0 is not covered.
Vaeth 2 start rating
Scoring: 25 is too much for a simple conventions lesson
Clarity: Users should not have to infer given data from i/o. Directions should clarify budget limitations for seniors, juniors, and to make the problem a little more interesting, an implementation of guest
ps the senior budget is 100 and the junior budget is 50. You need to use int to represent this, not double (I know, it's currency, but...)
maressalul - First example code does not work ... because of family.budgetLimit();.
- There is a problem with data check. I produce the same output and it is not recognisez as good.
adi341875 the same issue is with me also.
cf_chenfan My code gave the identical output as "expected", but it still said that wrong, why?
adi341875 The code constrain is very high. Even you are getting the correct output, it will be wrong. Hint # Dont change any other line neither increase any single line. You just have to give you the solution where it is required.
jayapal_02 You might commented code lines where you supposed to add and added your code in new line. Don't do that. Remove the lines and your code.
_clfm_ Clean & correct
Here are the five lines you have to modify - be careful not to change anything else. Let me know if you have any questions!
int budgetLimit() default 0; // 1 @FamilyBudget(userRole = "SENIOR", budgetLimit = 100) // 2 @FamilyBudget(userRole = "JUNIOR", budgetLimit = 50) // 3 int budgetLimit = family.budgetLimit(); // 4 if (spend <= budgetLimit) { // 5
(From my HackerRank repo on GitHub.)
vakasrimails I learned new things about Annotations.
kailiu All Passed. This question doesn't have to be medium. But it's really nice to motivate people to learn more about annotation.
import java.lang.annotation.*; import java.lang.reflect.*; import java.util.*; @Target(ElementType.METHOD) @Retention(RetentionPolicy.RUNTIME) @interface FamilyBudget { String userRole() default "GUEST"; int budget(); } class FamilyMember { @FamilyBudget(userRole="SENIOR", budget=100) public void seniorMember(int budget, int moneySpend) { System.out.println("Senior Member"); System.out.println("Spend: " + moneySpend); System.out.println("Budget Left: " + (budget - moneySpend)); } @FamilyBudget(userRole="JUNIOR", budget=50) public void juniorUser(int budget, int moneySpend) { System.out.println("Junior Member"); System.out.println("Spend: " + moneySpend); System.out.println("Budget Left: " + (budget - moneySpend)); } } public class Solution { public static void main(String[] args) { Scanner in = new Scanner(System.in); int testCases = Integer.parseInt(in.nextLine()); while (testCases > 0) { String role = in.next(); int spend = in.nextInt(); try { Class annotatedClass = FamilyMember.class; Method[] methods = annotatedClass.getMethods(); for (Method method : methods) { if (method.isAnnotationPresent(FamilyBudget.class)) { FamilyBudget family = method .getAnnotation(FamilyBudget.class); String userRole = family.userRole(); int budgetLimit = family.budget(); if (userRole.equals(role)) { if(spend<=budgetLimit){ method.invoke(FamilyMember.class.newInstance(), budgetLimit, spend); }else{ System.out.println("Budget Limit Over"); } } } } } catch (Exception e) { e.printStackTrace(); } testCases--; } } }
yli131 Did you guys even look at the codes? How could you write "userRole.equals(role)" as the last line in your input? Think about the relation between spend and budgetLimt, come on, do not just scroll down the discussions and copy codes from others
maximshen Good point ! I even feel Hackerrank should deduct some points due to looking at discuss portion before that person actually passed 50% of test cases.
Stormfather I understand the feeling, and I think there should be some sort of way to prevent people from looking at code before finishing, but I don't think you should be prevented from going to the discussion tab. I have had issues every now and then where I simply didn't understand what the problem was asking. I was able to write the required code, but I couldn't grasp what the requirements were. In these cases, I sometimes looked at the discussion tab to clarify. I almost did that for this problem, because I had never used annotations before and didn't know what it wanted from me. Fortunately, I found a helpful tutorial on annotations on another website that helped me solve it, but had I not found that I probably would have come here. Not for answers to the problem, just understanding of what was needed.
What I'm trying to say is that discussion should be allowed, even among people who have not yet solved the problem so that they may discuss possible issues and help each other understand. However, there should be some sort of system in place that prevents code from being posted in order to give answers to people who don't want to put any work in.
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