Interview Question

Hi I was wondering if someone could help me with this I always get this question alot in interviews and was hoping someone could help with an answers.

if i had 2 strings str1"abcde" and str2 "bcd" create a function that would take both the strings and see if the str1 contains str2 if so return the index of str1 where the str2 is located. if not return -1

Most of the times im using just a bunch of for loops and if statesment but is there a simpler approach to getting this done?

Well to be honest I find interview questions that make you reinvent the wheel completely pointless in assessing someone. There is a function which does this already and it is part of the library.

strstr()

strstr - C++ Reference

I'm pretty sure it's optimally implemented so you might want to take a look at its implementation.

If you are being asked to describe an algorithm without actually implementing it, then perhaps the interviewer is looking for something sophisticated, e.g., Boyer-Moore. If you are being asked to implement an algorithm on paper, or on a computer but within a very short period of time, then perhaps the interviewer is just checking that you have practical programming skills to develop and implement a simple algorithm, in which case "a bunch of for loops and if statesment" would suffice.

EDIT:
Or, if there is no requirement to develop a simple algorithm, then an extension of claudiu's suggestion is best, i.e., to demonstrate practical programming skills by writing a wrapper around an existing function to do exactly what is required.

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Originally Posted by kiros88

if i had 2 strings str1"abcde" and str2 "bcd" create a function that would take both the strings and see if the str1 contains str2 if so return the index of str1 where the str2 is located. if not return -1

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Code:

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int foo(void) {
    return 1;
}

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Quote:

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Originally Posted by JohnGraham

Code:

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int foo(void) {
    return 1;
}

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LOL. Nice one.

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Originally Posted by claudiu

LOL. Nice one.

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Except that it demonstrates JohnGraham's failure to read the requirements properly since the function has no parameters. Furthermore, although the language is a little ambiguous, the description does state certain steps that must be done, even if precomputation due to known input was feasible.

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Originally Posted by laserlight

Except that it demonstrates JohnGraham's failure to read the requirements properly since the function has no parameters. Furthermore, although the language is a little ambiguous, the description does state certain steps that must be done, even if precomputation due to known input was feasible.

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Actually, if we are talking requirements now, I think John got them spot on. The OP meant to say something else but said exactly what John pointed out. There is nowhere in the OP's original post a mention of the word "parameters".

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Originally Posted by claudiu

Actually, if we are talking requirements now, I think John got them spot on. The OP meant to say something else but said exactly what John pointed out. There is nowhere in the OP's original post a mention of the word "parameters".

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... create a function that would take both the strings ...

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that sounds like a request for parameters to me

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Originally Posted by ಠ_ಠ

that sounds like a request for parameters to me

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Well, I think we are going off subject here, but it really isn't a request for parameters, or rather not one expressed correctly. "taking the strings" could very well mean storing them in some function variables:

int func(void){
char *str1 = "hello";
char *str2 = "abcd";
}

Vague requirements are not really requirements.

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Originally Posted by claudiu

Vague requirements are not really requirements.

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if you ever try to implement that belief during an interview, please let me know ahead of time so I can come and watch


and yes, I agree, your example does count as "taking the strings"

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Originally Posted by ಠ_ಠ

if you ever try to implement that belief during an interview, please let me know ahead of time so I can come and watch


and yes, I agree, your example does count as "taking the strings"

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I do. I worked as a requirements engineer for several years.

Quote:

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Originally Posted by claudiu

"taking the strings" could very well mean storing them in some function variables:

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Excellent. Explain how did JohnGraham satisfy this interpretation of the "requirements".

Quote:

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Originally Posted by claudiu

Vague requirements are not really requirements.

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Agreed, but if so, clarify, rather than interpret, or if you really want to interpret, then be bulletproof.