Two Sum II - Input array is sorted

Input array is sorted

• Time: O(N)
• Space: O(1)

public int[] twoSum2(int[] nums, int target) {
    if (nums == null || nums.length == 0) return null;
    int i = 0;
    int j = nums.length - 1;
    while (i < j) {
        int x = nums[i] + nums[j];
        if (x < target) {
            i++;
        } else if (x > target) {
            j--;
        } else {
            return new int[]{i + 1, j + 1};
        }
    }
    return new int[]{};
}