Compilare: user.cpp: In function ‘int main()’: user.cpp:51:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<g[node].size(); j++) ^ user.cpp:23:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("bellmanford.in","r",stdin); ^ user.cpp:24:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("bellmanford.out","w",stdout); ^ user.cpp:26:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d",&N,&M); ^ user.cpp:31:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d",&x,&y,&c); ^