|시간 제한||메모리 제한||제출||정답||맞힌 사람||정답 비율|
|2 초||256 MB||11||7||7||70.000%|
Vera has N friends numbered from 0 to N − 1. Being in Software Engineering, all her friends do not have enough spare time to engage in relationships. However, friends have crushes on each other.
If x is a non-negative integer, let g(x) be the number of ones in the binary representation of x. Let f(i, j) = g((A · B(i·N+j))%M), where A, B, M are integer constants.
It is known that for any 2 friends i and j where i < j, if f(i, j) is even then i has a crush on j, otherwise j has a crush on i.
Vera thinks love triangles are very funny. A love triangle is a set of 3 friends i, j, k such that i has a crush on j, j has a crush on k and k has a crush on i.
Given integers N, M, A, B tell Vera how many love triangles exist among her friends. Two love triangles are different if they contain a different set of 3 friends.
The input will be in the format:
N M A B
Output one line with the number of love triangles.
3 5 3 4
3 3 1 2
1337 10007 1337 1337
Let a → b denote that friend a has a crush on friend b.
For the first example, f(0, 1) = g(2) = 1, f(0, 2) = g(3) = 2, f(1, 2) = g(2) = 1. So 0 → 2, 2 → 1, and 1 → 0, so there is one love triangle.
For the second example, 1 → 0, 2 → 0, and 2 → 1, so there are zero love triangles.