Freaks City

The problem involves finding the minimum number of vertices to remove from an undirected graph to make it disconnected. Problem Analysis When a graph becomes disconnected, there exist at least two vertices that cannot reach each other. We can enumerate these two vertices as source and sink, then determine the minimum number of other vertices th ...

A Given a sequence ${a_n}$, select the largest possible subset such that no two selected elements sum to a prime number. Constraints: $T \leq 4$, $n \leq 750$, $a_i \leq 10^9$. Identical values can be merged into counts. Note that at most one instance of 1 may be included. This becomes a bipartite graph problem: odd numbers connect to the sourc ...