First to find the first position of target, then the second position.

Code:

```
public class Solution {
public int[] searchRange(int[] A, int target) {
if (A == null || A.length == 0) {
return new int[]{-1, -1};
}
int first = -1, last = -1;
int start = 0, end = A.length-1, mid = -1;
// search for first position
while (start + 1 < end) {
mid = start + (end - start) / 2;
if (A[mid] >= target) {
end = mid;
} else {
start = mid;
}
// System.out.printf("start: %d, mid: %d, end: %d\n", start, mid, end);
}
if (A[start] == target) {
first = start;
} else if (A[end] == target) {
first = end;
}
start = 0; end = A.length - 1; mid = -1;
// search for last position
while (start + 1 < end) {
mid = start + (end - start) / 2;
if (A[mid] <= target) {
start = mid;
} else {
end = mid;
}
}
if (A[end] == target) {
last = end;
} else if (A[start] == target) {
last = start;
}
return new int[] {first, last};
}
}
```