Compilare: user.cpp: In instantiation of ‘int index(T, F, const std::vector<T>&, T, int) [with T = int; F = std::plus<int>]’: user.cpp:127:66: required from here user.cpp:63:12: warning: suggest parentheses around ‘+’ inside ‘<<’ [-Wparentheses] while (l+1<<h <= 2*n && f(c, t[l]) <= b) { ^ user.cpp:83:27: warning: suggest parentheses around ‘+’ inside ‘<<’ [-Wparentheses] } while (h >= 0 && !(l+1<<h <= 2*n && f(c, t[l]) <= b)); ^ user.cpp: In function ‘int main()’: user.cpp:93:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("aib.in", "r", stdin); ^ user.cpp:94:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("aib.out", "w", stdout); ^