How to replace two nested for with vectorization

How can I write this without loops

[nrows, ncols] = size(A);
for i = 1:nrows
    for j = 1:ncols
        if A(i,j)~=0
            AC(i) = AC(i)+C(i,A(i,j));
        else
            break
        end
    end
end

[KSSV]

Are you sure that AC in the above is an array?

[etudiant_is]

AC is a vector not an array

[KSSV]

It's dimension is equal to i.

Answer 1

[Walter Roberson]

maxA = max(A(:));
Ccopy = C;
Ccopy(:,maxA+1) = 0;
A(A==0) = maxA+1;
for i = 1 : nrows
  AC(i) = sum( C(sub2ind(size(C), 1:nrows, A(:,j))) );
end

Provided that in code before what was posted, AC was initialized to 0's. If AC was not initialized then replace the code with

error('This is the vectorized equivalent to broken code')

[etudiant_is]

yes AC has been initialized previously