LintCode Maximum Number in Mountain

description:
Given a mountain sequence of n integers which increase firstly and then decrease, find the mountain top.

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Example
Given nums = [1, 2, 4, 8, 6, 3] return 8
Given nums = [10, 9, 8, 7], return 10

使用二分法，二分法的关键点：二分出来的数据只有2个，对着两个数进行处理。

public class Solution {    /**     * @param nums a mountain sequence which increase firstly and then decrease     * @return then mountain top     */    public int mountainSequence(int[] nums) {        // Write your code here        if (nums == null || nums.length == 0) {            return 0;        }        int start = 0, end = nums.length - 1;        while (start + 1 < end) {            int mid = start + (end - start) / 2;            if (nums[mid] > nums[mid + 1]) {                end = mid;            } else {                start = mid;            }        }        return Math.max(nums[start], nums[end]);    }}