[leetCode] Search for a Range

Given a sorted array of integers, find the starting and ending position of a given target value.

Your algorithm's runtime complexity must be in the order of O(log n).

If the target is not found in the array, return 

[-1, -1]

.

For example,

Given 

[5, 7, 7, 8, 8, 10]

 and target value 8,

return 

[3, 4]

.

public class Solution {
public int[] searchRange(int[] nums, int target) {
int l = 0, r = nums.length - 1;
int[] res = new int[2];

while (l <= r) {
if (nums[l] == target && nums[r] == target) {
res[0] = l;
res[1] = r;
return res;
}
int m = (l + r)/2;
if (nums[m] < target) {
l = m + 1;
}
else if (nums[m] > target) {
r = m - 1;
}
else {
if (nums[l] != target)
l++;
if (nums[r] != target)
r--;
}
}
res[0] = -1; res[1] = -1;
return res;
}
}