Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:48:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[x].size(); ++ i) ^ user.cpp: In function ‘void Bfs()’: user.cpp:66:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[x].size(); ++ i) ^ user.cpp: In function ‘void mark(int)’: user.cpp:81:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[x].size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:23:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:27:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &c); ^ user.cpp: In function ‘void write()’: user.cpp:121:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &d); ^