Compilare: user.cpp: In function ‘int main()’: user.cpp:13:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%lld", &b); ^ user.cpp:16:3: warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] do { ^