Compilare: user.cpp: In function ‘int BFS(int)’: user.cpp:27:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graph[x].size();++i) ^ user.cpp: In function ‘void DFS(int)’: user.cpp:43:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graph[x].size();++i) { ^ user.cpp: In function ‘int BFS(int)’: user.cpp:37:12: warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized] return r; ^