Compilare: user.cpp: In function ‘int main()’: user.cpp:25:18: warning: unused variable ‘j’ [-Wunused-variable] int cnx=0,nc,j; ^ user.cpp:15:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&m); ^ user.cpp:18:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&x,&y); ^