LeetCode in Kotlin
3637. Trionic Array I
Easy
You are given an integer array nums of length n.
An array is trionic if there exist indices 0 < p < q < n − 1 such that:
nums[0...p]is strictly increasing,nums[p...q]is strictly decreasing,nums[q...n − 1]is strictly increasing.
Return true if nums is trionic, otherwise return false.
Example 1:
Input: nums = [1,3,5,4,2,6]
Output: true
Explanation:
Pick p = 2, q = 4:
nums[0...2] = [1, 3, 5]is strictly increasing (1 < 3 < 5).nums[2...4] = [5, 4, 2]is strictly decreasing (5 > 4 > 2).nums[4...5] = [2, 6]is strictly increasing (2 < 6).
Example 2:
Input: nums = [2,1,3]
Output: false
Explanation:
There is no way to pick p and q to form the required three segments.
Constraints:
3 <= n <= 100-1000 <= nums[i] <= 1000
Solution
class Solution {
fun isTrionic(nums: IntArray): Boolean {
var p = 0
var q = 0
val n = nums.size
for (i in 1..<n - 1) {
if (nums[i - 1] == nums[i]) {
return false
}
if (nums[i - 1] < nums[i] && nums[i] > nums[i + 1]) {
if (p != 0) {
return false
}
p = i
}
if (nums[i - 1] > nums[i] && nums[i] < nums[i + 1]) {
if (p == 0 || q != 0) {
return false
}
q = i
}
}
return q > 0
}
}