Compilare: user.cpp: In function ‘int main()’: user.cpp:78:10: warning: unused variable ‘k’ [-Wunused-variable] int n,k,i,j,ist; ^ user.cpp:78:14: warning: unused variable ‘j’ [-Wunused-variable] int n,k,i,j,ist; ^ user.cpp: In function ‘char nextch()’: user.cpp:9:31: 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,MAXBUF,fi); ^