Compilare: user.cpp: In function ‘int main()’: user.cpp:12:10: warning: variable ‘c’ set but not used [-Wunused-but-set-variable] char c; ^ user.cpp:13:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&n); ^ user.cpp:17:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,255,in); ^