Compilare: main.cpp: In function 'int main()': main.cpp:13:13: warning: iteration 1999998 invokes undefined behavior [-Waggressive-loop-optimizations] v[i]=0; ~~~~^~ main.cpp:12:19: note: within this loop for(i = 2; i <= 20000000; i++) ~~^~~~~~~~~~~ main.cpp:25:12: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized] out<<b*b; ^