#P5487. Minimal Linear Recurrence and Sequence Term Computation
Minimal Linear Recurrence and Sequence Term Computation
Minimal Linear Recurrence and Sequence Term Computation
Given a sequence P starting from index 0 and containing the first n terms, determine the minimal (shortest) homogeneous linear recurrence relation that generates this sequence modulo \(998244353\). Using this recurrence relation, compute and output the value of Pm modulo \(998244353\).
The recurrence relation is of the form:
[ P(n) = c_1 \cdot P(n-1) + c_2 \cdot P(n-2) + \cdots + c_L \cdot P(n-L),\quad \text{for } n \ge L, ]
where the coefficients \(c_1, c_2, \dots, c_L\) (with \(L\) being minimal) are determined from the given first n terms of P. If \(m < n\), simply output the given \(P_m\).
Note: All computations should be performed modulo \(998244353\), and any formulas must be written in \(\LaTeX\) format.
inputFormat
The first line contains two integers n
and m
(1 \le n \le 10^5
and 0 \le m \le 10^18
).
The second line contains n
space‐separated integers representing the first n
terms of the sequence P (\(P_0, P_1, \dots, P_{n-1}\)).
outputFormat
Output a single integer, which is \(P_m\) modulo \(998244353\).
sample
5 7
1 1 2 3 5
13