MAXMEX - Editorial

editorial
, , ,
19

I don’t think the set you mentioned latter has mex = 8. It is given in the question that we are to find the smallest positive number. It is not mentioned that it should belong to the given set.

1 Like
20

https://www.codechef.com/viewsolution/34615406

can someone help me what was wrong with my code??
pls review this code…

21

yeah, nor they mentioned that multiple occurences are possible, I am not supposed to keep looking up in the comment section for clarification.

5 Likes
22

smallest positive integer which does not occur among the chosen elements

We are choosing a particular subset from the given set and checking MEX for that subset

3 Likes
23

Sorry, it was a typing mistake.

24

Even I made the same mistake :frowning:

25

They give two statements themselves
Editorial : MEX of a sequence is the smallest positive integer not present in the sequence.
Problem: MEX, i.e. the smallest positive integer which does not occur among the chosen elements.
These two statement are not similiar
@taran_1407

5 Likes
26

The answer in this case is -1.

27

MEX of a sequence is the smallest positive integer not present in the sequence.
So in subsequence {4,5,6,7,9,10} it will be 1 as 1 is the smallest positive number not present in the subsequence.

28

Please explain your approach. Did you consider multiple occurence of integers?

29

I think the problem statement could have been made a little more clear with 1 or 2 more input-output examples.

6 Likes
30

How though?

31

I made the same incorrect assumption and ended up solving only one question :’(

1 Like
32

Unless specified that array elements are unique, you ought to assume that only.

1 Like
33

You are right bro

34

MEX, i.e. the smallest positive integer which does not occur among the chosen elements

M=3
Given set = {1, 2, 4}
Acc to answer chosen set is {1, 2, 3}. So the elements which donot occur among the chosen elements are : NULL
Smallest among NULL is 3? Please explain

1 Like
35

When you are using the word among the elements , it signify that you are using some lower and upper bound

3 Likes
36

made the same assumption :pensive:

37

Because

Editorial : MEX of a sequence is the smallest positive integer not present in the sequence.
Problem: MEX, i.e. the smallest positive integer which does not occur among the chosen elements.

chosen elements is a subset of sequence

38

Yeah, but which elements you chose depends on you.