Search through a vector and replace numbers at specific indices with the index

So this question is really hard to ask probably because it is so easy to answer. But I could really use some help. I have a 100 by 1 vector A. For any number in A I want to make sure the number located at its index is that actual number. If it's a different, I would like to replace it with its index.

For example at index 2, we have 1, but if we look at vector A, 2 appears at index 8, I want to replace the 1 at index 2, with 2. Also at index 6, we have 1 but if we scan through vector A, 6 appears at index 11, I would like to replace the 1 at index 6 with 6 and so forth. Thank you in advance!

A=[1 1 3 4 5 1 7 2 9 5 6 12 1 4 3 16 1 9 1 16 3 4 23 10 4 21 18 5 6 12 11 4 27 5 12 12 4 5 3 12 12 12 9 12 34 1 12 34 31 3 8 9 3 54 4 27 3 11 1 60 31 9 9 24 9 12 9 7 23 4 5 1 5 12 1 3 5 1 23 1 24 3 4 9 18 26 7 21 5 9 1 3 5 11 25 4 7 14 23 21]

The answer looks something like this

answer=[1 2 3 4 5 6 7 8 9 10 11 12 1 14 3 16 1 18 1 16 21 4 23 24 25 26 27 5 6 12 31 4 27 34 12 12 4 5 3 12 12 12 9 12 34 1 12 34 31 3 8 9 54 54 4 27 3 11 60 60 31 9 9 24 9 12 9 7 23 4 5 1 5 12 1 3 5 1 23 1 24 3 4 9 18 26 7 21 5 9 1 3 5 11 25 4 7 14 23 21];

The code should be something like this I think, but this is not giving me the answer am looking for.

B=(1:100 ); for v=1:n if B(v)==any(A(v)) A(v)=B(v) end end

Answer 1

[KSSV]

Instead of replacing, you can striaght away generate a row vector from 1 to 100? This is your output eh? Still, you can do like below:

A=[1 1 3 4 5 1 7 2 9 5 6 12 1 4 3 16 1 9 1 16 3 4 23 10 4 21 18 5 6 12 11 4 27 5 12 12 4 5 3 12 12 12 9 12 34 1 12 34 31 3 8 9 3 54 4 27 3 11 1 60 31 9 9 24 9 12 9 7 23 4 5 1 5 12 1 3 5 1 23 1 24 3 4 9 18 26 7 21 5 9 1 3 5 11 25 4 7 14 23 21];
pos = 1:length(A) ;
% get indices equal positions 
idx = A==pos ;

%%If not replace

A(~idx) = pos(~idx) ;

I hope, I got your question correct. :)

[puttogether]

I want to replace a number with the index of its location only if there is another number within A equal to that index. The resulting vector looks like this

A=[1 1 3 4 5 1 7 2 9 5 6 12 1 4 3 16 1 9 1 16 3 4 23 10 4 21 18 5 6 12 11 4 27 5 12 12 4 5 3 12 12 12 9 12 34 1 12 34 31 3 8 9 3 54 4 27 3 11 1 60 31 9 9 24 9 12 9 7 23 4 5 1 5 12 1 3 5 1 23 1 24 3 4 9 18 26 7 21 5 9 1 3 5 11 25 4 7 14 23 21];

answer=[1 2 3 4 5 6 7 8 9 10 11 12 1 14 3 16 1 18 1 16 21 4 23 24 25 26 27 5 6 12 31 ... 4 27 34 12 12 4 5 3 12 12 12 9 12 34 1 12 34 31 3 8 9 54 54 4 27 3 11 60 60 31 9 9 24 9 12 9 7 23 4 5 1 5 12 1 3 5 1 23 1 24 3 4 9 18 26 7 21 5 9 1 3 5 11 25 4 7 14 23 21];