Compilare: user.cpp: In function ‘int main()’: user.cpp:54:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &n); ^ user.cpp:56:43: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%lf%lf", &v[i].x, &v[i].y); ^ user.cpp:68:13: warning: ‘p’ may be used uninitialized in this function [-Wmaybe-uninitialized] aux = v[p]; v[p] = v[0]; v[0] = aux; ^