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
        if (nums == null) {
            return -1;
        }
        
        int[] dum = new int[nums.length+2];
        dum[0] = Integer.MIN_VALUE;
        dum[dum.length-1] = Integer.MIN_VALUE;

        for(int i = 0; i < nums.length; i++) {
            dum[i+1] = nums[i];
        }

        int left = 0;
        int mid = 1;
        int right = 2;

        while (right < dum.length) {
            if (dum[left] < dum[mid] && dum[mid] > dum[right]) {
                return mid-1;
            }
            left++;
            mid++;
            right++;
        }
        return -1;
    }
}