Searching for single element in dichotomy

A daily topic ing, Today is a day medium topic 540. Single Element in a Sorted Array

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