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].

• Time: O(n)
• Space: O(1)

public int[] searchRange(int[] nums, int target) {
    int[] ret = {-1, -1};
    if (nums.length == 0) return ret;
    int l = 0, r = nums.length - 1, start, end;
    while (l <= r) {
        int mid = (l + r) / 2;
        if (nums[mid] < target) {
            l = mid + 1;
        } else {
            r = mid - 1;
        }
    }
    start = l;
    l = 0;
    r = nums.length - 1;
    while (l <= r) {
        int mid = (l + r) / 2;
        if (nums[mid] <= target) {
            l = mid + 1;
        } else {
            r = mid - 1;
        }
    }
    end = r;
    if (end >= start) {
        ret[0] = start;
        ret[1] = end;
    }
    return ret;
}