class Solution {
public:
    vector<int> searchRange(vector<int>& nums, int target) {
        if (nums.empty()) {
            return {-1, -1};
        }
        int l = 0, r = nums.size() - 1;

        while (l < r) { // 找第一个target
            int mid = l + r >> 1;
            if (nums[mid] >= target) r = mid;
            else l = mid + 1;
        }
        int t = l;

        if (target != nums[r]) return {-1, -1};


        l = 0, r = nums.size() - 1;
        while (l < r) { //找最后一个是target
            int mid = l + r + 1 >> 1;
            if (nums[mid] <= target) l = mid; 
            else r = mid - 1;
        }
        int k = r;

        return {t, k};
    }
};