Compilare: main.cpp: In function 'll calc(std::__cxx11::string)': main.cpp:25:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp: In function 'll before(std::__cxx11::string, int, int)': main.cpp:32:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(dec>=s.size())return 1e7; ~~~^~~~~~~~~~ main.cpp: In function 'll after(std::__cxx11::string, int, int)': main.cpp:41:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;dec<s.size();dec++,ans++) ~~~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:100:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rebus.in", "r", stdin); ^ main.cpp:101:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rebus.out", "w", stdout); ^