Problem Description: Given a non-negative integer N, find the number of i, such that C(N, i) % 2 == 0 and 0 ≤ i ≤ N.Constraints: 0 ≤ N ≤ 1e18Solution: According Lucas's theorem, since we are considering modulo 2, we can observe that i can …

Problem Description: There are K kinds of colors, each with at least one instance of object. There are C[i] number of instances of color i. You are to arrange them into a ring, and you want to know how many different kinds of rings could b…

Problem Description: There are 6 kinds of coins, with units 1, 5, 10, 50, 100, 500, respectively. You have infinite number of each of them. You are to deal with T test cases, and in each case you will be given a value M, where you should o…