LeetCode-in-Java
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
public class Solution {
public boolean isTrionic(int[] nums) {
int i = 1;
int n = nums.length;
while (i < n && nums[i] > nums[i - 1]) {
i++;
}
if (i == n || i == 1) {
return false;
}
while (i < n && nums[i] < nums[i - 1]) {
i++;
}
if (i == n) {
return false;
}
while (i < n && nums[i] > nums[i - 1]) {
i++;
}
return i == n;
}
}