题目链接

思路一：

思路二：

int findPeakElement(int* nums, int numsLen ) {
    // write code here
    int left=0;
    int right=numsLen-1;
    int* cur=nums;
    int mid=0;

    //特殊情况判断两个值，单增和单减
    if(cur[0]>cur[1])
    {
        return 0;
    }
    if(cur[numsLen-1]>cur[numsLen-2])
    {
        return numsLen-1;
    }

    //普遍情况
    while(left<right)
    {
        //中间下标
        mid=((left+right)/2);
        //其他的正常判断
        //上升
        if((cur[mid-1]<cur[mid])&&(cur[mid]<cur[mid+1]))
        {
            left=mid;
        }
        //下降
        else if((cur[mid-1]>cur[mid])&&(cur[mid]>cur[mid+1]))
        {
            right=mid;
        }
        //谷底
         else if((cur[mid-1]>cur[mid])&&(cur[mid]<cur[mid+1]))
        {
           left=mid;
        }
        //峰值
        else if((cur[mid-1]<cur[mid])&&(cur[mid]>cur[mid+1]))
        {
            return mid;
        }    
    }
    return -1;
}