852. Peak Index in a Mountain Array | Easy
The solution contained is naive approach and can be improved much better.
Problem:
Let's call an array A a mountain if the following properties hold:
A.length >= 3
There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1]
Given an array that is definitely a mountain, return any i such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1].
Example 1:
Input: [0,1,0]
Output: 1
Example 2:
Input: [0,2,1,0]
Output: 1
Note:
3 <= A.length <= 10000
0 <= A[i] <= 10^6
A is a mountain, as defined above.
Accepted 47,112 Submissions 69,111
My attempt
class Solution:
def peakIndexInMountainArray(self, A):
"""
:type A: List[int]
:rtype: int
"""
"""
# initial approach - naive solution
# 108ms, 0.88% on speed
_index = 0
_elem = 0
for index, elem in enumerate(A):
if elem > _elem:
_index = index
_elem = elem
return _index
"""