Compilare: user.cpp: In function ‘int main()’: user.cpp:31:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<v[i].size(); j++) ^ user.cpp:44:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<v[i].size(); j++) ^ user.cpp:14:40: 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:15:42: 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:17:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:23:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&ww); ^