Compilare: user.cpp: In function ‘int query(int, int)’: user.cpp:31:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:46:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < euler.size(); ++ i) ~~^~~~~~~~~~~~~~ user.cpp:49:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; 1 << i <= euler.size() - 1; ++ i) { ~~~~~~~^~~~~~~~~~~~~~~~~~~ user.cpp:50:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j + (1 << i) <= euler.size(); ++ j) { ~~~~~~~~~~~~~^~~~~~~~~~~~~~~