Compilare: user.cpp: In function ‘void doit(int)’: user.cpp:25:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<X[x].size();i++) ^ user.cpp:29:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<X[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:48:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen ("judete.in","r",stdin); freopen ("judete.out","w",stdout); ^ user.cpp:48:69: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen ("judete.in","r",stdin); freopen ("judete.out","w",stdout); ^ user.cpp:49:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d",&n,&m); ^ user.cpp:52:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d",&a,&b); ^