Package g1601_1700.s1694_reformat_phone_number

Class Solution

  • public class Solution
extends Object
    1694 - Reformat Phone Number.

    Easy

    You are given a phone number as a string number. number consists of digits, spaces ' ', and/or dashes '-'.

    You would like to reformat the phone number in a certain manner. Firstly, remove all spaces and dashes. Then, group the digits from left to right into blocks of length 3 until there are 4 or fewer digits. The final digits are then grouped as follows:

    • 2 digits: A single block of length 2.
    • 3 digits: A single block of length 3.
    • 4 digits: Two blocks of length 2 each.

    The blocks are then joined by dashes. Notice that the reformatting process should never produce any blocks of length 1 and produce at most two blocks of length 2.

    Return the phone number after formatting.

    Example 1:

    Input: number = “1-23-45 6”

    Output: “123-456”

    Explanation: The digits are “123456”.t

    Step 1: There are more than 4 digits, so group the next 3 digits. The 1st block is “123”.

    Step 2: There are 3 digits remaining, so put them in a single block of length 3. The 2nd block is “456”.

    Joining the blocks gives “123-456”.

    Example 2:

    Input: number = “123 4-567”

    Output: “123-45-67”

    Explanation: The digits are “1234567”.

    Step 1: There are more than 4 digits, so group the next 3 digits. The 1st block is “123”.

    Step 2: There are 4 digits left, so split them into two blocks of length 2. The blocks are “45” and “67”.

    Joining the blocks gives “123-45-67”.

    Example 3:

    Input: number = “123 4-5678”

    Output: “123-456-78”

    Explanation: The digits are “12345678”.

    Step 1: The 1st block is “123”.

    Step 2: The 2nd block is “456”.

    Step 3: There are 2 digits left, so put them in a single block of length 2. The 3rd block is “78”.

    Joining the blocks gives “123-456-78”.

    Constraints:

    • 2 <= number.length <= 100
    • number consists of digits and the characters '-' and ' '.
    • There are at least two digits in number.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • reformatNumber

        public String reformatNumber​(String number)