P1029 [NOIP 2001 Junior] Greatest Common Divisor and Least Common Multiple Problem
Description
Given two positive integers $x_0, y_0$, find the number of pairs $P, Q$ that satisfy the following conditions:
1. $P, Q$ are positive integers.
2. $P, Q$ have greatest common divisor $x_0$ and least common multiple $y_0$.
Compute the number of all possible pairs $(P, Q)$ that satisfy the conditions.
Input Format
One line with two positive integers $x_0, y_0$.
Output Format
One line with a single number, representing the number of pairs $P, Q$ that satisfy the conditions.
Explanation/Hint
There are 4 possibilities for $P, Q$:
1. $3, 60$.
2. $15, 12$.
3. $12, 15$.
4. $60, 3$.
Constraints: For $100\%$ of the testdata, $2 \le x_0, y_0 \le 10^5$.
Source: NOIP 2001 Junior, Problem 2.
Translated by ChatGPT 5