Compilare: user.cpp: In function ‘int main()’: user.cpp:171:11: warning: unused variable ‘a2’ [-Wunused-variable] int a,a2; ^ user.cpp: In function ‘char get()’: user.cpp:19:32: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, size, in); ^ user.cpp: In function ‘int main()’: user.cpp:168:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&l,&c); ^