[LeetCode]34. Search for a Range

public class Solution {
public int[] searchRange(int[] nums, int target) {
int[] res = {-1, -1};
if (nums == null || nums.length == 0) {
return res;
}
int beg = 0;
int end = nums.length - 1;
while (beg <= end) {
int mid = beg + (end - beg) / 2;
if (nums[mid] >= target) {
end = mid - 1;
} else {
beg = mid + 1;
}
}
res[0] = beg < nums.length && nums[beg] == target ? beg : -1;
beg = 0;
end = nums.length - 1;
while (beg <= end) {
int mid = beg + (end - beg) / 2;
if (nums[mid] <= target) {
beg = mid + 1;
} else {
end = mid - 1;
}
}
res[1] = end >= 0 && nums[end] == target ? end : -1;
return res;
}
}