Compilare: main.cpp: In function 'int bs(int, std::vector<int>&)': main.cpp:9:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(best+(1<<step) < v.size() && v[best+(1<<step)] <= x) best += (1<<step); ~~~~~~~~~~~~~~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:18:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cautbin.in", "r", stdin); ^ main.cpp:19:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cautbin.out", "w", stdout); ^