SkyWT

NOIP 提高组 题解聚合（（伪）完结撒花！）

2019.11.07 Upd：其实不是真的完结了，有些题目实在搞不动 QwQ

D - Power Products

CodeForces Round #578 Div2 题解

Codeforces Round #578 (Div. 2)

D - White Lines

Description

*1900

CodeForces Round #581 Div2 题解

Codeforces Round #581 (Div. 2) 比赛链接：LInk

C - Anna, Svyatoslav and Maps

Description

Ivan wants to make a necklace as a present to his beloved girl. A necklace is a cyclic sequence of beads of different colors. Ivan says that necklace is beautiful relative to the cut point between two adjacent beads, if the chain of beads remaining after this cut is a palindrome (reads the same forward and backward).

Description

Yaroslav has n points that lie on the $Ox$ axis. The coordinate of the first point is $x_1$, the coordinate of the second point is $x_2$, ..., the coordinate of the n-th point is — $x_n$. Now Yaroslav wants to execute $m$ queries, each of them is of one of the two following types:

Description

In mathematical terms, the sequence $F_n$ of Fibonacci numbers is defined by the recurrence relation

$$F_1 = 1; F_2 = 1; F_n = F_{n - 1} + F_{n - 2} (n> 2)$$

DZY loves Fibonacci numbers very much. Today DZY gives you an array consisting of n integers: $a_1, a_2, \dots, a_n$. Moreover, there are $m$ queries, each query has one of the two types:

$$C[i,j]=\sum_{k=1}^{b} A[i,k]\ast B[k,j]$$