Compilare: user.cpp: In function ‘void leaga(int)’: user.cpp:16:11: warning: statement has no effect [-Wunused-value] for(ln;ln<lln+n;++ln) ^ user.cpp: In function ‘int main()’: user.cpp:31:46: warning: iteration 15u invokes undefined behavior [-Waggressive-loop-optimizations] for(int i=2;i<=61;++i)a[i]=(a[i-1]+1)*2-1; ^ user.cpp:31:5: note: containing loop for(int i=2;i<=61;++i)a[i]=(a[i-1]+1)*2-1; ^