Compilare: main.cpp: In function 'bool bellman(int, long long int)': main.cpp:29:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[u].size(); i++) ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:48:27: warning: variable 'last' set but not used [-Wunused-but-set-variable] long long dr=0,st,med,last; ^~~~ main.cpp:45:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] { freopen("ciclu.in", "r", stdin); ^ main.cpp:46:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ciclu.out", "w", stdout); ^ main.cpp:49:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:51:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &z); ^