Compilare: main.cpp: In function 'long long int euler(long long int)': main.cpp:23:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<pri.size()&&pri[j]<=x){ ~^~~~~~~~~~~ main.cpp:33:17: warning: 'nr' may be used uninitialized in this function [-Wmaybe-uninitialized] eul[x]=eul[x/nr]*ans; ~^~~ main.cpp:33:21: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized] eul[x]=eul[x/nr]*ans; ~~~~~~~~~^~~~