Watch 10 video solutions for Reformat Phone Number, a easy level problem involving String. This walkthrough by NeetCode has 186,659 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
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:
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". 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 <= 100number consists of digits and the characters '-' and ' '.number.