162. Find peak - binary search

class Solution {
    
public:
    int findPeakElement(vector<int>& nums) {
    
        // Parts must be orderly , When there is no peak , The array must be in ascending or descending order 
        int n = nums.size();
        if(n == 1 || nums[0] > nums[1])
            return 0;
        if(nums[n - 1] > nums[n - 2])
            return n - 1;
        int left = 0, right = n - 1, mid;
        while(left <= right){
    
            mid = (left + right) / 2;
            if(nums[mid] > nums[mid - 1] && nums[mid] > nums[mid + 1]){
    
                break;
            }
            else if(nums[mid] > nums[mid - 1]){
    
                left = mid + 1; // Right will not touch the far right , So you can  + 1
            }
            else{
    
                right = mid;    // If it's here  - 1, You may encounter the leftmost , Cause the above if Beyond the boundary 
            }
        }
        return mid;
    }
};

Accepted
63/63 cases passed (0 ms)
Your runtime beats 100 % of cpp submissions
Your memory usage beats 63.44 % of cpp submissions (8.6 MB)