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Hi everyone, let's do this question.

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Given a string s, find the length of the longest substring without repeating characters.

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Now let's try to understand this question.

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Let's say the string which is given to us is x y z xp.

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So this can be a string right now.

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In this case, what are the substrings which are possible.

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We can have just x, we can just have y, we can just have Z etc..

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Right.

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So this is like a substring with length one.

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We could have x y we can have y z etc..

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So there are various substrings which are possible.

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But we can see that the longest substring without repeating characters is this one over here right y

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z xp.

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And this has a length of four.

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So this is the question.

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We need to find the longest substring without repeating characters.

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And then we have to return the length of that substring.

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So that is what is being asked to us.

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Now let's go ahead and write a few test cases for this question.

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Let's say the string which is given to us is pee pee pee pee pee.

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So in this case the longest substring over here would be just pee.

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Right?

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Because if you just take two pees, you are repeating a character.

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So in this case the length is equal to one.

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Now let's say the string which is given to us is a b c b c, c d.

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In this case the length has to be three, right?

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Which is this over here a b c.

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Now if you take this b you cannot take it right because you are repeating two B's.

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Again if you take if you start from here, you just have a substring of two characters.

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If you start from B, if you start from C, also you have a substring of two characters without repeating

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characters, right?

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So again, you can see this is the longest substring without repeating characters, and it has a length

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of three.

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Now what if the string which is given to us is this one over here?

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Now in this case, you can see that the longest substring without repeating characters is this over

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here, right.

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Starting at R and going to W.

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And this has a length of seven.

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All right.

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So this is the question.

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We have understood the question.

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Remember in the interview feel free to ask any clarifying questions you have.

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And also uh, you you can come up with test cases together with the interviewer.

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So you can say if you can ask the interviewer if he or she is ready to come up with some test cases

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together.

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So this will ensure that you have clearly understood the question, and this will prepare you to solve

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the question.

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Now, in the next video, let's try to think how we can solve this question.