Compilare: user.cpp: In function ‘int main()’: user.cpp:58:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[a[i]].size()==fr[a[i]]-k) ~~~~~~~~~~~~~~^~~~~~~~~~~~ user.cpp:60:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[a[i]].size()>=fr[a[i]]-k) ~~~~~~~~~~~~~~^~~~~~~~~~~~ user.cpp: In function ‘unsigned int getint()’: user.cpp:25:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,maxb,1,fin),ptr=0; ^ user.cpp:30:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,maxb,1,fin),ptr=0; ^