vector<int> searchRange(vector<int>& nums, int target) {
int idx1 = lower_bound(nums, target);
int idx2 = lower_bound(nums, target+1)1;
if (idx1 < nums.size() && nums[idx1] == target)
return {idx1, idx2};
else
return {1, 1};
}
int lower_bound(vector<int>& nums, int target) {
int l = 0, r = nums.size()1;
while (l <= r) {
int mid = (rl)/2+l;
if (nums[mid] < target)
l = mid+1;
else
r = mid1;
}
return l;
}
C++ binary search solution (lower_bound implementation).


@caikehe great job! much tight and clean than mine
Here is my solution, I used a bit slower way but it works.
Step1. Binary search for the target
Step2. Search towards left and rightclass Solution { public: vector<int> searchRange(vector<int>& nums, int target) { int left_binary = 0; int right_binary = nums.size()  1; int mid; int start = 1; //initailize as 1 int end = 1; vector<int> result; //Step1. Binary search for the target while(left_binary <= right_binary) { mid = (left_binary + right_binary) / 2; if(nums[mid] == target) { start = end = mid; //record the index } if(nums[mid] > target){right_binary = mid  1;} else{left_binary = mid + 1;} } //Step2. search towards left and right while(start > 0 && nums[start  1] == target){ start;} while(end < nums.size()  1 && nums[end + 1] == target){ ++end;} result.push_back(start); result.push_back(end); return result; } };