LeetCode - Refresh - Search for a Range

 1 class Solution {
 2 public:
 3     int bsearch(int A[], int start, int end, int target) {
 4         int index = -1, mid = 0;
 5         while (start <= end) {
 6             mid = (start + end)/2;
 7             if (A[mid] <= target) {
 8                 start = mid + 1;
 9                 index = mid;
10             } else {
11                 end = mid - 1;
12             }
13         }
14         return index;
15     }
16     vector<int> searchRange(int A[], int n, int target) {
17         vector<int> result(2, -1);
18         result[0] = bsearch(A, 0, n-1, target-1) + 1;
19         result[1] = bsearch(A, 0, n-1, target);
20         if (result[0] == -1 || A[result[0]] != target) {
21             return vector<int> (2, -1);
22         }
23         return result;
24     }
25 };