Compilare: main.cpp: In function 'int main()': main.cpp:44:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(x>=0 && x<v.size()) cout<<x<<"\n"; else cout<<"-1\n"; ~^~~~~~~~~ main.cpp:24:34: 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:25:36: 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); ^