dynkinToPartition -- converts a highest weight written in the basis of fundamental dominant weights for type A into a partition

There are at least two popular ways to describe irreducible $\gl_n$ and $sl_n$ characters. We can either give its highest weight as a linear combination of the fundamental dominant weights $\omega_i$, or describe it as a partition. This function allows us to convert from the first convention to the second.

In the example below, we convert the weight $\lambda = (1,2,0,0,1) = \omega_1 + 2\omega_2 + \omega_5$ for $sl_6$ into a partition.