The warmth of the T1 is coming.
T2T3 very God.
T1.
will not
T2.
Inclusion and exclusion, very God
T3.
The card often stuck out 10. I do not like the examination room. . . . . (Although $ O (n) $ over $ 1e8 $ inherently not OK)
The examination room:
Crazy simplified formula, probably the last
$n^{2}-\sum\limits_{i=1}^{n}{g(i)\frac{n}{i}}$
Where $ G (x) $ 2 $ ^ represents the number of prime factors {x} $ different
After the test:
In fact, $ f (x) Positive Solution $ is $ prefix g (x) $ and, we can first linear violence sieved $ n ^ {\ frac {2} {3}} $ below $ f (x) $, the remaining issues connected with the root of the screen.
The idea stuck point: the original prefix and may seek inclusion and exclusion. . . . Du exam glazing want to teach a sieve. . . . .