A peak element is an element that is greater than its neighbors.
Given an input array where num[i] ≠ num[i+1], find a peak element and return its index.
The array may contain multiple peaks, in that case return the index to any one of the peaks is fine.
You may imagine that num[-1] = num[n] = -∞.
For example, in array [1, 2, 3, 1], 3 is a peak element and your function should return the index number 2.
python code:
class Solution:
# @param nums, an integer[]
# @return an integer
def findPeakElement(self, nums):
if len(nums)==1 or nums[0]>nums[1]: #边界条件判定
return 0
else:
for i in range(1,len(nums)-1):
if nums[i]>nums[i-1] and nums[i]>nums[i+1]: #第2个到第n-1个的判定
return i
else: #for正常结束，第n个为peak number
return len(nums)-1
leetcode Find Peak Element python
原文：http://www.cnblogs.com/bthl/p/4574516.html