What kind of data structure should I use for this in C++
<p>I need something to represent a sequence of sequences of pairs, like this: </p>

<p><code>[((1,2) (1,3)) ((1,2) (1,4) (1,5))].</code> </p>

<p>I also need to append the sequences of pairs freely to make one sequence of pairs, like this <code>append.[((1 2)(3 4)) ((5 6))] = ((1 2)(3 4)(5 6)).</code> Is there anything that is simple to use in C++ that could let me manipulate my data like this?</p>
