```
class Solution {
public:
int findPeakElement(vector<int>& nums) {
int l = 0, r = nums.size() - 1;
while(l < r){
int mid = l + (r - l)/2;
if(nums[mid] > nums[mid + 1]) r = mid;
else l = mid + 1;
}
return l;
}
};
```