MLE '19 Contest 4 P9 - Poggers

View as PDF

Submit solution

Points: 7
Time limit: 2.0s
Memory limit: 512M

Problem type

An array a of N integers can be transformed into a new array through this process:

  • a_i is modified to be the maximum of a_i and a_{i+1} for all 1 \le i < N.

An array is stable if it remains the same after the above transformation is performed on the array. For example, [2,1,1,1] is a stable array.

It can be proven that array a, after a certain number of transformations, will result in a stable array. Can you print out the minimum number of transformations on array a to transform it into a stable array?

Input Specification

The first line will contain the integer N (1 \le N \le 10^5).

The second line will contain the array a (1 \le a_i \le 10^6).

Output Specification

Output the number of minimum transformations to transform a into a stable array.

Sample Input

1 3 2 4 5

Sample Output



  • -1
    MstrPikachu  commented on Dec. 30, 2019, 3:38 p.m.

    How can a_N be modified to be the maximum of a_N and a_{N+1}?

    • 2
      wleung_bvg  commented on Dec. 31, 2019, 8:32 a.m.

      a_N is never modified. Note that the problem statement mentions that we only modify a_i for 1 \le i < N.