Compilare: user.cpp: In function ‘int main()’: user.cpp:25:38: warning: format ‘%lf’ expects argument of type ‘double*’, but argument 3 has type ‘long double*’ [-Wformat=] fscanf(fin, "%lf %lf", &x[i], &y[i]); ^ user.cpp:25:38: warning: format ‘%lf’ expects argument of type ‘double*’, but argument 4 has type ‘long double*’ [-Wformat=] user.cpp:34:37: warning: format ‘%lf’ expects argument of type ‘double’, but argument 3 has type ‘long double’ [-Wformat=] fprintf(fout, "%.6lf\n", area / 2.0); ^ user.cpp:22:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^ user.cpp:25:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%lf %lf", &x[i], &y[i]); ^