Compilare: user.cpp: In function ‘int main()’: user.cpp:56:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<nr[j].size()) ^ user.cpp:13:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&n,&k); ^ user.cpp:15:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&x); ^