162.寻找峰值

二分法

class Solution {
    public int findPeakElement(int[] nums) {
        int low = 0, high = nums.length - 1;
        while (low < high) {
            int mid = (low + high)>>1;
            if (nums[mid] < nums[mid + 1])
                low = mid + 1;
            else high = mid;
        }
        return low;
    }
}