Day 42.2.txt

1694. Reformat Phone Number

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".
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".
Example 4:

Input: number = "12"
Output: "12"
Example 5:

Input: number = "--17-5 229 35-39475 "
Output: "175-229-353-94-75"
 

Constraints:

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




class Solution {
    public String reformatNumber(String n) {
        int a[]=new int[n.length()];
        int i,j=0,k;
        for(i=0;i<n.length();i++)
        {
            if(n.charAt(i)>='0'&&n.charAt(i)<='9')
                a[j++]=Integer.parseInt(String.valueOf(n.charAt(i)));
        }
        n="";
        if(j<=3)
        {
            for(i=0;i<j;i++)
            {
                n=n+a[i];
            }
            return n;
        }
        for(i=0;i<j;)
        {
            if(j-i==4)
            {
                for(k=i;k<i+2;k++)
                {
                    n=n+a[k];
                }
                n=n+"-";
                for(;k<j;k++)
                {
                    n=n+a[k];
                }
                i=j;
            }
            else if(j-i<4)
            {
                for(k=i;k<j;k++)
                {
                    n=n+a[k];
                }
                i=j;
            }
            else
            {
                for(k=i;k<i+3;k++)
                {
                    n=n+a[k];
                }
                i+=3;
                n=n+"-";
            }
        }
        return n;
    }
}