简洁的二分代码

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