Compilare: user.cpp: In function ‘int find_common(int, int, int)’: user.cpp:38:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < gr[node].size(); ++i) { ^ user.cpp: In function ‘void bfs(int, int)’: user.cpp:58:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < gr[node].size(); ++i) { ^ user.cpp:47:20: warning: unused variable ‘parent’ [-Wunused-variable] int node, nxt, parent; ^