2 problems

Let $G$ be a $2$-connected graph of order $n\ge 10$. Let $K_n$ denote the complete graph, and let $K_n^2$ and $K_n^{n-2}$ be the graphs obtained from $K_{n-1}$ by adding one vertex…

Let $G$ be a connected graph and let $B_1,\ldots,B_k$ be all its non-complete blocks, of respective orders $n_1,\ldots,n_k$. Define the Szeged–Wiener difference by…