【数论推导】Educational Codeforces Round 106 Problem D: The Number of Pairs
D-TheNumberofPairs传送门题目大意:给定c,d,xc,d,xc,d,x,找出有多少对正整数对(a,b)(a,b)(a,b)满足下述等式:c•lcm(a,b)−d•gcd(a,b)=xc•lcm(a,b)-d•gcd(a,b)=xc•lcm(a,b)−d•gcd(a,b)=x解题思路:c•lcm(a,b)−d•gcd(a,b)=x;lcm(a,b)=a•bgcd(a,b);c•a•b