"Use c$++$ to write code for these two functions.

int Related$($int id$\_1,$ int id$\_2)$ const: Returns the length of the shortest path between node id$\_1$ and node id$\_2($i$.$e$.$ shortest length between person$1$ and person$2)$ if such path exists; otherwise, return $-1.$

int Related $($int id$\_1,$ int id$\_2,$ const std::string& relationship$)$: Returns the length$*$ of the shortest path between node with id$\_1$ and node with id$\_2$ where all edges in XQ$09$ the path are relationship $($i$.$e$.$ shortest length between person$1$ and person$2$ for the only given relationship$)$ if such path exists; otherwise, return $-1.$

We have a vector relation that store the relationship between two people. And a map$>$ graph$\_$ that stores vertices and adjacency list."