Given n , k , find the number of pairs (i,j) such that 0<=i<j<=n and k divides (j-i)↵
Testcases up to 1e5 , (k<=n) up to 1e9 ↵
Sample:-↵
input: ↵
2↵
3 1↵
5 2↵
output : ↵
6↵
(5,2) , output 6
Testcases up to 1e5 , (k<=n) up to 1e9 ↵
Sample:-↵
input
2↵
3 1↵
5 2↵
output : ↵
6↵