Compilare: user.cpp: In function ‘int main()’: user.cpp:11:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi, "%lld", &n); ^ user.cpp:16:59: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi, "%lld%lld%lld%lld", &x1, &y1, &x2, &y2); ^ user.cpp:29:27: warning: ‘xout’ may be used uninitialized in this function [-Wmaybe-uninitialized] nr += xin - xout + 1; ^