Compilare: main.cpp: In function 'int main()': main.cpp:46:9: warning: unused variable 'x' [-Wunused-variable] int x; ^ main.cpp: In function 'char next_char()': main.cpp:16:32: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,dim,stdin); ^ main.cpp: In function 'int main()': main.cpp:41:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("secventa.in","r",stdin); ^ main.cpp:42:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("secventa.out","w",stdout); ^