Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:27:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<conex[node].size(); ++i) ^ user.cpp: In function ‘void bellmanford()’: user.cpp:49:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<G[node].size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:88:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biperm.in", "r", stdin); ^ user.cpp:89:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biperm.out", "w", stdout); ^ user.cpp:93:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:96:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &up[i]); ^ user.cpp:98:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &down[i]); ^