Compilare: main.cpp: In function 'int main()': main.cpp:104:7: warning: unused variable 'sz' [-Wunused-variable] int sz = dv.size(); ^~ main.cpp: In function 'char read_ch()': main.cpp:57:35: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(_in_buff, 1, 131072, _fin); ^ main.cpp: In function 'int main()': main.cpp:79:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("tenerife.out", "w", stdout); ^