Compilare: main.cpp: In function 'int euler(int)': main.cpp:29:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ main.cpp: In function 'int main()': main.cpp:52:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<r.size()-1;i++) { ~^~~~~~~~~~~