题解 | 寻找峰值

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param nums int整型一维数组 
     * @return int整型
     */
    public int findPeakElement (int[] nums) {
        // write code here
        //首先看看两边有没有峰值
        if (nums.length == 1 || nums[0] > nums[1]) {
            return 0;
        }
        if (nums[nums.length - 1] > nums[nums.length - 2]) {
            return nums.length - 1;
        }
        int left = 1;
        int right = nums.length - 2;
        while (left <= right) {
            int mid = left + (right - left) / 2;
            if (nums[mid] > nums[mid - 1] && nums[mid] > nums[mid + 1]) {
                return mid;
            } else if (nums[mid] < nums[mid + 1]) {  //在“爬坡”,峰值在右边
                left = mid + 1;
            } else {  //在下坡，峰值在左边
                right = mid - 1;
            }
        }
        return left;
    }
}