MWC '15 #7 P1: Sequences

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Points: 3
Time limit: 2.0s
Memory limit: 256M
Author:
aurpine
Problem type

kushanzaveri loves sequences. However, he finds that the grade 11 categorizations of sequences are too easy.

Sequences have 4 categories:

  • Arithmetic: Consecutive terms have a constant difference.
  • Geometric: Consecutive terms have a constant factor (multiple).
  • Both: Both an arithmetic and geometric sequence.
  • Random: Not an arithmetic nor geometric sequence.

kushanzaveri says:

Categorizing a sequence is an easy P1 of a contest.

Input Specification

The first line will contain a single integer N (3 \le N \le 10), the number of elements in the sequence.

The second line will contain N integers, E_n, the n^\text{th} element. (-1000 \le E_n \le 1000).

Output Specification

arithmetic, geometric, both, or random depending on the type of sequence.

Sample Input 1

4
1 3 9 27

Sample Output 1

geometric

Sample Input 2

5
-1 2 -3 4 -5

Sample Output 2

random

Comments


  • 0
    kittycornanna1  commented on April 15, 2024, 11:19 p.m.

    A lot of the submissions are wrong before I looked at the problem closely I though it was kinda hard.


  • -4
    XTTH  commented on Feb. 15, 2019, 12:40 a.m.

    0, 0, 0, 0 is not a geometric sequence.


    • 2
      kingW3  commented on Feb. 15, 2019, 11:18 a.m.

      It depends on definition but it is 0,0\cdot 2,0\cdot 2^2,0\cdot 2^3