Compilare: user.cpp: In function ‘void johnsons_alg(std::vector<Node>*, int, std::priority_queue<Node>, int*, bool, int (*)[500])’: user.cpp:147:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j<G[i].size(); j++){ ~^~~~~~~~~~~~ user.cpp: In function ‘void read_data(int&, std::vector<Node>*)’: user.cpp:43:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:46:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^