gudii9
asked on
caughtSpeeding java challenge
Hi,
I am trying below challenge
http://codingbat.com/prob/p157733
i am failing two test cases as above. Please advise
I am trying below challenge
http://codingbat.com/prob/p157733
public int caughtSpeeding(int speed, boolean isBirthday) {
int result;
if(speed<=65){
if(speed<=60&& isBirthday==true){
return result=0;
}
else {
return result=0;
}
}
else if(speed<=85){
if(speed<=61&& isBirthday==true){
return result=1;
}
else {
return result=1;
}
}
return result=2;
}
Expected Run
caughtSpeeding(60, false) → 0 0 OK
caughtSpeeding(65, false) → 1 0 X
caughtSpeeding(65, true) → 0 0 OK
caughtSpeeding(80, false) → 1 1 OK
caughtSpeeding(85, false) → 2 1 X
caughtSpeeding(85, true) → 1 1 OK
caughtSpeeding(70, false) → 1 1 OK
caughtSpeeding(75, false) → 1 1 OK
caughtSpeeding(75, true) → 1 1 OK
caughtSpeeding(40, false) → 0 0 OK
caughtSpeeding(40, true) → 0 0 OK
caughtSpeeding(90, false) → 2 2 OK
other tests
X
i am failing two test cases as above. Please advise
SOLUTION
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ASKER CERTIFIED SOLUTION
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17: else if(speed >= 61 && speed <= 80 + allowableTolerance){
speed >= 61 &&
is unnecessary
speed >= 61 &&
is unnecessary
speed >= 61 &&
is unnecessary
Mathematically, you are absolutely correct. However I prefer to write it in this way since I believe it expresses the requirement clearly.
If you are trying to express the requirements, shouldn't it be
speed >= 61+allowableTolerance
speed >= 61+allowableTolerance
you "could" write it that way if you wanted to.
However tolerance is applicable to upper limit of the range.
Its purely debatable, depends on individual coding style.
However tolerance is applicable to upper limit of the range.
Its purely debatable, depends on individual coding style.
The requirements say 5 higher in all cases so it should also apply to the lower range.
Had the tests been reversed,
if( speed >= 61+ allowableTolerance && speed <= 80 + allowableTolerance){
return SMALL_TICKET;
}
if(speed <= 60 + allowableTolerance){
return NO_TICKET;
}
would still give correct results, but
if( speed >= 61 && speed <= 80 + allowableTolerance){
return SMALL_TICKET;
}
if(speed <= 60 + allowableTolerance){
return NO_TICKET;
}
would give incorrect results.
The only reason you can get away with a test that does not express the requirement is that the order of the tests makes it unnecessary.
A test that is both incorrect and unnecessary is not expressing the requirement clearly
Had the tests been reversed,
if( speed >= 61+ allowableTolerance && speed <= 80 + allowableTolerance){
return SMALL_TICKET;
}
if(speed <= 60 + allowableTolerance){
return NO_TICKET;
}
would still give correct results, but
if( speed >= 61 && speed <= 80 + allowableTolerance){
return SMALL_TICKET;
}
if(speed <= 60 + allowableTolerance){
return NO_TICKET;
}
would give incorrect results.
The only reason you can get away with a test that does not express the requirement is that the order of the tests makes it unnecessary.
A test that is both incorrect and unnecessary is not expressing the requirement clearly
excellent
ASKER
public int caughtSpeeding(int speed, boolean isBirthday) {
int result = 0;
if(speed<60||(isBirthday&&speed<=65)){
result=0;
}
else if((speed>=61&&speed<=80)||(isBirthday&&(speed>=61&&speed<=85))){
result=1;
}
else if(speed>=81||(isBirthday&&speed>=85)){
result=2;
}
return result;
}
i changed my approach bit as above and passing all tests. please advise on any improvements?
people have already posted improved solutions. take a look.
public int caughtSpeeding(int speed, boolean isBirthday) {
int small = limit(60, isBirthday);
int big = limit(80, isBirthday);
return speed <= small ? 0 : speed <= big ? 1 : 2;
}
private int limit(int speed, boolean isBirthday) {
return isBirthday ? speed + 5: speed;
}
ASKER
if( isBirthday ){ speed -= 5; }
return speed<=60?0:speed<=80?1:2;
not clear on above solution.
if isBirthday is true then speed=speed-5 then returning ternary(speed<=60?0:speed<
ternary is speed is less then or equal to 60 then 0 ticket if false then check speed <=80 if true then 1 if false ie beyond 80 then 2 ticket right?
what is the use of
speed=speed-5
Please advise
"on that day, your speed can be 5 higher in all cases"
ASKER
return speed <= small ? 0 : speed <= big ? 1 : 2;
how to comprehend statement with more than two , three ternary statements as above.
I got true part.
I did not get false part.
If false we are saying return
speed <= big ? 1 : 2;//here again checking if true 1 and false 2.. i am not clear here.
please advise
how to comprehend statement with more than two , three ternary statements as above.
Try putting brackets in place if it helps your understanding.
but your code executes
if(speed<=65){ // true
if(speed<=60&& isBirthday==true){ // false
...
}
else {
return result=0; // wrong
}
}
caughtSpeeding(85, false) → 2
but your code executes
if(speed<=65){ // false
...
}
else if(speed<=85){ // true
if(speed<=61&& isBirthday==true){ // false
,,,
}
else {
return result=1; // wrong
}
}