I found a really interesting problem and I wanted to hear people's opinion.
It has to do with currency exchange rate.
If we are give some coins $c_1,c_2,\dots,c_n$ and an array $R$ that keeps the selling price, where $R[i,j]$ is the selling price of one unit of currency $c_i$ to currency $c_j$.
a) We are trying to design an algorithm that will find a sequence of coins $(c_{i_1}, c_{i_2}, \dots, c_{i_k})$ ,$R[i_1, i_2] \cdot R[i_2, i_3] \cdots R[i_{k-1}, i_k] \cdot R[i_k, i_1] >1$.
b) Show how the algorithm you designed can find and print fast such a sequence $(c_{i_1}, c_{i_2}, \dots, c_{i_k})$ (if there is one).
If someone dives into that problem it would be also interesting to know the execution time of the algorithm.
Sorry if I did mistakes with the terminology of this scientific field.