#P3873. Weather Forecast Prediction
Weather Forecast Prediction
Weather Forecast Prediction
A company’s weather forecasting system encodes the weather of a day as an integer between 0 and 4146 (inclusive). The forecast for a future day is computed using the weather observations from the previous n days. Specifically, if wi denotes the weather condition on day i (with i > n), then the following recurrence is used:
\(w_i = (a_1 \times w_{i-1} + a_2 \times w_{i-2} + \cdots + a_n \times w_{i-n}) \mod 4147\)
Here, a1, a2, \dots, an are known constant coefficients. Given the weather conditions for the first n days, your task is to predict the weather condition on the mth day.
inputFormat
The input consists of three lines:
- The first line contains two integers n and m (1 ≤ n ≤ m). Here, n is the number of initially given days and m is the day for which the weather prediction is required.
- The second line contains n integers: w1, w2, ..., wn, each representing the weather condition of that day (0 ≤ wi ≤ 4146).
- The third line contains n integers: a1, a2, ..., an, representing the coefficients used in the recurrence.
Note: For m ≤ n, simply output the mth weather condition.
The recurrence is defined as follows for i > n:
\(w_i = (a_1 \times w_{i-1} + a_2 \times w_{i-2} + \cdots + a_n \times w_{i-n}) \mod 4147\)
outputFormat
Output a single integer, which is the predicted weather condition on the mth day.
sample
3 5
1 2 3
1 1 1
11