#K45372. Counting Mountain Valleys
Counting Mountain Valleys
Counting Mountain Valleys
The problem asks you to determine the number of "mountain valleys" in an array of heights. A mountain valley is defined as a contiguous subarray a[l...r]
(with 1 \le l < r \le n
) in which there exists an index m such that
[ a[l] > a[l+1] > \cdots > a[m] \quad \text{and} \quad a[m] < a[m+1] < \cdots < a[r] ]
Your task is to count the number of such valleys for each test case.
Note: A valid valley must have at least three elements.
inputFormat
The first line of input contains an integer t
representing the number of test cases. Each test case consists of two lines:
- The first line contains an integer
n
, the number of elements in the array. - The second line contains
n
space-separated integers representing the height values.
outputFormat
For each test case, output a single integer on a new line representing the count of mountain valleys in the array.
## sample2
5
10 8 7 12 15
4
1 2 3 4
1
0
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