Compilare: user.cpp: In function ‘int main()’: user.cpp:103:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[x].size(); i++) ^ user.cpp:77:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("catun.in","r",stdin); ^ user.cpp:78:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("catun.out","w",stdout); ^ user.cpp:79:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&k); ^ user.cpp:83:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a); ^ user.cpp:93:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %lld",&a,&b,&c); ^