Transforming a row (inside a matrix) with equal numbers into a row with only one number

I have amatrix of the following type:

in = [228 228 228
231	231	231
183	183	183
157	157	157
168	168	168];

I need to know if the 3 columns of each row are equal and, if they are, get an Rx1 matrix at the end:

out = [228; 231; 183; 157; 168];

If they are not, keep the initial matrix Rx3 ('in' matrix) and tell me in which row the values of the three columns are not the same.

in_new = [228 228 228
231	231	231
183	200	183
157	157	157
168	168	200];
out_new = [3;5];

Answer 1

[Dyuman Joshi]

in1 = [228 228 228
231	231	231
183	183	183
157	157	157
168	168	168];

[a1, b1] = transform(in1)

a1 = 5×1

228 231 183 157 168

b1 =

     []

in2 = [228 228 228
231	231	231
183	200	183
157	157	157
168	168	200];

[a2, b2] = transform(in2)

a2 = 5×3

228 228 228 231 231 231 183 200 183 157 157 157 168 168 200

b2 = 2×1

3 5

function [out, out_new] = transform(in)
idx = all(~diff(in, [], 2), 2);
if all(idx)
    out = in(:,1);
    out_new = [];
else
    out = in;
    out_new = find(~idx);
end
end