PatreonOA #2
Sum of Subarray Regions
估计中等可在线判题
考点(AI 标注)单调栈与堆
The region of each position is the longest contiguous interval that contains the position and in which its height is still the maximum; equal heights still count as the maximum.
The standard input/output conventions and constraints added by this site are described under "Input".
输入格式
n≤100000, heights 1..10^9.
输出格式
Output the sum of the lengths of all regions.
样例 1
输入:
3
3 5 6
输出:
6
样例 2
输入:
2
5 5
输出:
4
样例 3
输入:
3
2 1 2
输出:
7
样例 4
输入:
4
1 3 2 4
输出:
9