CF1485C Floor and Mod

A pair of positive integers $ (a,b) $ is called special if $ \lfloor \frac{a}{b} \rfloor = a \bmod b $ . Here, $ \lfloor \frac{a}{b} \rfloor $ is the result of the integer division between $ a $ and $ b $ , while $ a \bmod b $ is its remainder. You are given two integers $ x $ and $ y $ . Find the number of special pairs $ (a,b) $ such that $ 1\leq a \leq x $ and $ 1 \leq b \leq y $ .

N/A

N/A

In the first test case, the only special pair is $ (3, 2) $ . In the second test case, there are no special pairs. In the third test case, there are two special pairs: $ (3, 2) $ and $ (4, 3) $ .