MATLAB: How to add value at end of row in a matrix

matrix manipulation

It is a very basic question but I could not figure how to do it without a for loop.
I have two vectors R and C of same length
R'=[2 4 5 2]
C'=[1 3 6 7]
I want to have
A= 
[0 0
 1 7
 0 0
 3 0
 6 0]
Basically R is for the rows and I want to have the content of C in the corresponding row in matrix A
If I do
    A(R)=C
it is going to be a vector not a matrix and the newest value will erase the oldest value in each row
A(R,:) will assign the value to the whole line which is not also what I want.
how can I increase the index of the column if there is more than one entry for each row?

Best Answer

Without any loops:
R = [2;4;5;2];
C = [1;3;6;7];
[~,X] = sort(R);
[~,~,Y] = unique(R);
Z = accumarray(Y,ones(size(R)),[],@(v){v});
Y(X) = cell2mat(cellfun(@cumsum,Z,'UniformOutput',false));
A = zeros(max(R),max(Y));
A(sub2ind(size(A),R,Y)) = C
creates this output:
A =
   0   0
   1   7
   0   0
   3   0
   6   0
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