Compilare: user.cpp: In function ‘int main()’: user.cpp:54:9: warning: unused variable ‘l’ [-Wunused-variable] int l=nextnum(), c=nextnum(), n=nextnum(); ^ user.cpp:54:22: warning: unused variable ‘c’ [-Wunused-variable] int l=nextnum(), c=nextnum(), n=nextnum(); ^ user.cpp: In function ‘char nextch()’: user.cpp:13:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fi); ^