leetcode

classSolution {
public:
vector<int>searchRange(vector<int>&nums, inttarget) {
if(nums.empty()) return {-1,-1};
intl=0, r=nums.size() -1; //二分范围while( l<r)                   //查找元素的开始位置        {
intmid= (l+r )/2;
if(nums[mid] >=target) r=mid;
elsel=mid+1;
        }
if( nums[r] !=target) return {-1,-1};  //查找失败intL=r;
l=0, r=nums.size() -1;     //二分范围while( l<r)                   //查找元素的结束位置        {
intmid= (l+r+1)/2;
if(nums[mid] <=target ) l=mid;
elser=mid-1;
        }
return {L,r};
    }
};