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gudii9Flag for United States of America

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scoreUp challenge

Hi,

I am working on below challenge
http://codingbat.com/prob/p180365



The "key" array is an array containing the correct answers to an exam, like {"a", "a", "b", "b"}. the "answers" array contains a student's answers, with "?" representing a question left blank. The two arrays are not empty and are the same length. Return the score for this array of answers, giving +4 for each correct answer, -1 for each incorrect answer, and +0 for each blank answer.


i was not clear on above description.

i was not clear how below result is 6 etc. please advise
scoreUp(["a", "a", "b", "b"], ["a", "c", "b", "c"]) → 6
scoreUp(["a", "a", "b", "b"], ["a", "a", "b", "c"]) → 11
scoreUp(["a", "a", "b", "b"], ["a", "a", "b", "b"]) → 16
ASKER CERTIFIED SOLUTION
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Guy Hengel [angelIII / a3]
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ASKER

giving +4 for each correct answer, -1 for each incorrect answer, and +0 for each blank answer.

simply looping the array, comparing the values at the same indices, and depending on the values, sum up the scores...
i think i got it now


scoreUp(["a", "a", "b", "b"], ["a", "c", "b", "c"]) → 6

as 'a' is same in both array give +4
then a not same as c so -1
then b same as b +4
then b not same as c -1

total is 6

let me think on pseudo code and code now
yes, exactly
don't forget to code for the "blank" answers
Avatar of gudii9

ASKER

public int scoreUp(String[] key, String[] answers) {
  int count=0;
  for(int i=0;i<key.length;i++){
    if(( (!key[i].equals("?")) &&(!answers.equals("?")) &&(key[i]==answers[i]))){
      count=count+4;
    }else{
      count=count-1;
    }
  }
  return count;
}

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above failing below tests. please advise
Expected      Run            
scoreUp(["a", "a", "b", "b"], ["a", "c", "b", "c"]) → 6      6      OK      
scoreUp(["a", "a", "b", "b"], ["a", "a", "b", "c"]) → 11      11      OK      
scoreUp(["a", "a", "b", "b"], ["a", "a", "b", "b"]) → 16      16      OK      
scoreUp(["a", "a", "b", "b"], ["?", "c", "b", "?"]) → 3      1      X      
scoreUp(["a", "a", "b", "b"], ["?", "c", "?", "?"]) → -1      -4      X      
scoreUp(["a", "a", "b", "b"], ["c", "?", "b", "b"]) → 7      6      X      
scoreUp(["a", "a", "b", "b"], ["c", "?", "b", "?"]) → 3      1      X      
scoreUp(["a", "b", "c"], ["a", "c", "b"]) → 2      2      OK      
scoreUp(["a", "a", "b", "b", "c", "c"], ["a", "c", "a", "c", "a", "c"]) → 4      4      OK      
scoreUp(["a", "a", "b", "b", "c", "c"], ["a", "c", "?", "?", "a", "c"]) → 6      4      X      
scoreUp(["a", "a", "b", "b", "c", "c"], ["a", "c", "?", "?", "c", "c"]) → 11      9      X      
scoreUp(["a", "b", "c"], ["a", "b", "c"]) → 12      12      OK      
other tests
X
The challenge states  
"?" representing a question left blank.
this will appear in the "answers" array. Therefore the following  
(!key[i].equals("?"))

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is not necessary. Your errors occur when there is a "?" in the answers. When it is found you add -1. That is wrong.
I confirm, and that is what I meant by:

don't forget to code for the "blank" answers
Avatar of gudii9

ASKER

The challenge states  
"?" representing a question left blank.
this will appear in the "answers" array. Therefore the following  
(!key[i].equals("?"))


is not necessary. Your errors occur when there is a "?" in the answers. When it is found you add -1. That is wrong.

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what i supposed to do when i see question mark(?)
Avatar of gudii9

ASKER

public int scoreUp(String[] key, String[] answers) {
  int count=0;
  for(int i=0;i<key.length;i++){
    if(( (!key[i].equals("?")) &&(!answers.equals("?")) &&(key[i]==answers[i]))){
      count=count+4;
    }else if(key[i].equals("?")){
      count=0;
    }else if(answers[i].equals("?")){
      count=0;
    }else{
      count=count-1;
    }
  }
  return count;
}

Open in new window


something like above?
I am failing some tests. please advise
Expected      Run            
scoreUp(["a", "a", "b", "b"], ["a", "c", "b", "c"]) → 6      6      OK      
scoreUp(["a", "a", "b", "b"], ["a", "a", "b", "c"]) → 11      11      OK      
scoreUp(["a", "a", "b", "b"], ["a", "a", "b", "b"]) → 16      16      OK      
scoreUp(["a", "a", "b", "b"], ["?", "c", "b", "?"]) → 3      0      X      
scoreUp(["a", "a", "b", "b"], ["?", "c", "?", "?"]) → -1      0      X      
scoreUp(["a", "a", "b", "b"], ["c", "?", "b", "b"]) → 7      8      X      
scoreUp(["a", "a", "b", "b"], ["c", "?", "b", "?"]) → 3      0      X      
scoreUp(["a", "b", "c"], ["a", "c", "b"]) → 2      2      OK      
scoreUp(["a", "a", "b", "b", "c", "c"], ["a", "c", "a", "c", "a", "c"]) → 4      4      OK      
scoreUp(["a", "a", "b", "b", "c", "c"], ["a", "c", "?", "?", "a", "c"]) → 6      3      X      
scoreUp(["a", "a", "b", "b", "c", "c"], ["a", "c", "?", "?", "c", "c"]) → 11      8      X      
scoreUp(["a", "b", "c"], ["a", "b", "c"]) → 12      12      OK      
other tests
X
Avatar of gudii9

ASKER

public int scoreUp(String[] key, String[] answers) {
  int count=0;
  for(int i=0;i<key.length;i++){
    if(( (!key[i].equals("?")) &&(!answers.equals("?")) &&(key[i]==answers[i]))){
      count=count+4;
    }else if(key[i].equals("?")){
      count=0;
    }else if(answers[i].equals("?")){
      count=count+0;
    }else if(!answers[i].equals(key[i])){
      count=count-1;
    }
  }
  return count;
}

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something like above.
Above passes all tests.
any improvements or alternate approaches? please advise
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ASKER

i see your point.

public int scoreUp(String[] key, String[] answers) {
  int count=0;
  for(int i=0;i<key.length;i++){
    if(( (!answers.equals("?")) &&(key[i]==answers[i]))){
      count=count+4;
    }/*else if(key[i].equals("?")){
      continue;
    }*/else if(answers[i].equals("?")){
      count=count+0;
    }else if(!answers[i].equals(key[i])){
      count=count-1;
    }
  }
  return count;
}

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above looks ok? any improvements, alternate approaches?
above looks ok?
It looks ok, but you could clean it up to improve readability.
public int scoreUp(String[] key, String[] answers) {
  int count = 0;
  for(int i=0;i<key.length;i++){
    if(answers[i].equals("?"))continue;
    if(key[i]==answers[i]){
      count = count + 4;
    }else count--;
  }
  return count;
}

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Avatar of gudii9

ASKER

why you chose if with if then else approach rather than
if with else if with else approach as i did ?
any specific advantage or disadvantage?
any specific advantage or disadvantage?
I just thought it was clearer.