Compilare: user.cpp: In function ‘int main()’: user.cpp:29:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d%d%d", &x, &y, &n, &r); ^ user.cpp:34:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &dir); ^ user.cpp:60:35: warning: ‘ar’ may be used uninitialized in this function [-Wmaybe-uninitialized] fprintf(fout, "%d", n * n - ar); ^