Compilare: user.cpp: In function ‘int main()’: user.cpp:45:35: warning: format ‘%lf’ expects argument of type ‘double’, but argument 3 has type ‘long double’ [-Wformat=] fprintf(OUT,"%.2lf\n",abs(ans)); ^ user.cpp:31:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(IN,"%d",&N); ^ user.cpp:34:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(IN,"%d%d",&X,&Y),v[i]={X,Y}; ^