Answer 1

Line 55 you are using == instead of =

Is this falling short of one case?

Answer 2

Manav Roy your solution exposes a hole in the Code Coach test cases. (There are many in Code Coach tasks!)

This input should result in "quiet", but your solution gives false "ALARM":

$xxGxTxxGxx

The issue is that only the last guard position gets tested in your code. Apparently Code Coach tests don't cover this case.

Answer 3

Just adding my 2 cents, here is a solution that I used when I did not resort to regex or string manipulation: I used a finite state machine (essentially implementing the regex manually).

Two states are of importance
- MONEY, when the money symbol was read, and
- THIEF, when a thief was encountered.

A state transition MONEY-> THIEF or vice versa triggers an alarm. I am in the habit of naming the initial state IDLE. It shows the state the machine is in before it even started processing an input string. Encountering a guard sets the machine back to IDLE.

We get the following state transitions:
IDLE (x,G) -> IDLE
IDLE (T) -> THIEF
IDLE ($) -> MONEY
THIEF (x,T) -> THIEF
THIEF ($) -> "ALARM"
THIEF (G) -> IDLE
MONEY (x) -> MONEY
MONEY (T) -> "ALARM"
MONEY (G) -> IDLE

where S(c) -> T means, "in state S, on char 'c' transition to state T".

"ALARM" short-circuits the process to display ALARM. All states are valid end states. If the end of string has been reached, output "quiet".

Just a different idea 🙂

Answer 4

Jackie oh, now I see how it works. In fact, the guard position is not even relevant. You could delete the line that finds g. Good job!

Answer 5

Brian
Ended up using Jackie 's clever approach.

Eliminate the x and check if T is in front or behind $.

The guard is irrelevant.

But there are those edge cases for empty casino, only the money, only the thief...things that could break the code.

The c# code looks so much cleaner though.
Rewritten code should be able to pass Brian's $xxGxTxxGxx test.

This code is so janky. See Mohammed 's code on how to properly write a c++ code.

https://code.sololearn.com/cqu5mc56c0ZW/?ref=app

Answer 6

Well, i did it this way to solve with C 🙂 I just did not want to present any codes at this time, but merely a different strategy. Interesting and educational, perhaps, especially for those who have never worked with finite state machines before 🙂 Bob_Li

Answer 7

Pardon my harshness in my critique, but your approach is pretty much a mess, and its correctness practically unprovable.

Some issues:

There are several code exit points, which makes it hard to trace, where execution ends

There are assertion failures. (For example, CheckPreceeding asserts that CasinoArray[index] == '#x27; on entry.)

CheckPreceeding does not cover all possibilities.

Fixing CasinoArray to size 8 may be a too conservative an estimate.

Apart from that you cout 'quiet' with single quotes, and you have an assignment where you need to have a comparison.

Answer 8

"Could there be 2 money index?"
Nope, I don't think so.

Decreasing index by one makes it accidentally correct, I would say. Correcter it would be to pass the index as the function requires (adapt the calling code to the requirements of the callee, not the other way around).

The remaining problem is, that CheckPreceeding does not cover all possibilities, as I had mentioned in my previous response.

Answer 9

Manav Roy I think your index adjustment to CheckPreceeding was what it needed most. I do not see the change updated in your Code Bits.

Maybe also increase the size of CasinoArray as Ani Jona 🕊 indicated.

Answer 10

Approach is correct. But main point if it not working, is lies in how you finding index values??
Note : a<b and b<c then always a<c. No need to check..

Answer 11

= is assignment operator
== is comparison operator
a=1 assigns 1 to a
a==1 returns true if a=1 else return false.

Answer 12

Yes. I guessed same but stange it passed all cases as per @Manav!!
test cases may don't have this case.

Answer 13

Jackie the OP was asking about C++, not C#.

In C++, use string.find() method.

Answer 14

I know. but it helps knowing how it's done in another language usually when I struggle I see what the algorithm is in another language and it helps...C# can be one of the difficult languages

Answer 15

String.find and indexOf does the same thing you see that I'm getting at...

Answer 16

Jackie does your code pass the Code Coach tests? It has a logic hole that is similar to the OP's code. Yours only checks the first occurrance of guard position. There can be more than one guard.

Answer 17

😊 yip it pass the test

Answer 18

Evaluate a given floor of the casino to determine if there is a guard between the money and the thief, if there is not, you will sound an alarm.

It clearly states to first check "if there is a guard between the money and the thief" so it wil be logical to check the first occurrence of the guard..
"if there is not, you will sound an alarm."
There's other ways aswel like checking if guard is correct position then check if not but it a lot quicker to check it the guard isn't doing its job....

Answer 19

Bob_Li

https://code.sololearn.com/c7n3l7586FqU/?ref=app

Answer 20

Ani Jona 🕊
That was very good approach.
It never occurred to me to view the problem as a state machine. The short-circuiting part sounds interesting.
So only the money and the thief triggers the alarm.
But you still have to code the idea. Is there a procedure for that? I mean, a process of converting the concept and insight to code?