题解 | 二分查找-I

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