Medium
最早接觸刷題剛學Binary Search那時候的習題，現在還是印象深刻，九章的老師講得很好這一部分.
class Solution {
public int[] searchRange(int[] nums, int target) {
if (nums == null || nums.length == 0){
return new int[]{-1, -1};
}
int first = -1, last = -1;
int start = 0;
int end = nums.length - 1;
while (start + 1 < end){
int mid = start + (end - start) / 2;
if (nums[mid] >= target){
end = mid;
} else {
start = mid;
}
}
if (nums[start] == target){
first = start;
} else if (nums[end] == target){
first = end;
}
if (first == -1){
return new int[]{-1, -1};
}
start = first;
end = nums.length - 1;
while (start + 1 < end){
int mid = start + (end - start) / 2;
if (nums[mid] > target){
end = mid;
} else {
start = mid;
}
}
if (nums[end] == target){
last = end;
} else if (nums[start] == target){
last = start;
}
return new int[]{first, last};
}
}
