Documentation Index
Fetch the complete documentation index at: /llms.txt
Use this file to discover all available pages before exploring further.
Tested Python solution for LeetCode 852 with 18 pytest cases. Generate a practice environment with lcpy.
lcpy gen -n 852 # by problem number
lcpy gen -s peak_index_in_a_mountain_array # by problem name
arr of length n where the values increase to a peak element and then decrease.
Return the index of the peak element.
Your task is to solve it in O(log(n)) time complexity.
Input: arr = [0,1,0]
Output: 1
Input: arr = [0,2,1,0]
Output: 1
Input: arr = [0,10,5,2]
Output: 1
class Solution:
# Time: O(log n)
# Space: O(1)
def peak_index_in_mountain_array(self, arr: list[int]) -> int:
left, right = 0, len(arr) - 1
while left < right:
mid = (left + right) // 2
if arr[mid] < arr[mid + 1]:
left = mid + 1
else:
right = mid
return left
| Time | Space |
|---|---|
| O(log n) | O(1) |