Find value in a cell array if you have its index

I have a cell array which has vectors as cells.I have an array containing some indices.I need from that indices to find the corresponding values of the cell array.For example

A{1,1}=[35,9,45,7];
A{2,1}=[21,4,65,3,11];
A{3,1}=[14,32];

and

B=[2;5;1];

I need to get

C=[9;11;14]

Which is the faster way?

my suggestion is

for ia=1:lenght(A)
 C=A{ia}(B(ia));
end

Answer 1

[Andrei Bobrov]

n = cellfun(@numel,A);
ii = cumsum(n);
x = [A{:}];
out = x(B+[0;ii(1:end-1)]);

Answer 2

[Azzi Abdelmalek]

You can use

C1=cellfun(@(x,ii) x(ii),A,num2cell(B))';

But your for loop is faster, do not forget the pre-allocation

C2=zeros(1,numel(B));
for ia=1:numel(B)
  C2(1,ia)=A{ia}(B(ia));
end