Find Peak Element

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.

找到一个波峰元素。特殊情况是最后一个大于倒数第二个，也算波峰。

public int findPeakElement(int[] nums) {if(nums==null||nums.length<2)return 0;if(nums[nums.length-1]>nums[nums.length-2])return nums.length-1;for(int i=1;i<nums.length-1;i++){if(nums[i]>nums[i-1]&&nums[i]>nums[i+1])return i;}return 0;}