ZigZag Conversion ๐
The ZigZag Conversion problem asks you to convert a given string into a new string by reordering the characters in a specific pattern determined by the number of rows.
Approach ๐
Input Validation ๐
- If the input string is empty, has only one character, or the number of rows is 1, return the input string as it is, as thereโs no need for conversion in these cases.
Initialization ๐
- Initialize an empty string
ans
to store the converted result. - Get the length
n
of the input string. - Initialize an index variable
ind
to 0 and a row counterr
to 0.
Conversion Logic โ๏ธ
- Iterate through each row, from row 0 to
numRows - 1
. - In each row, iterate through the input string, adding characters to the result string
ans
.
Character Appending โ๏ธ
- Append the current character to
ans
. - If we are not in the first row, last row, and thereโs a valid next character within the string bounds:
- Append the character at an offset of
2 * i
from the current position, wherei
is the current row.
- Append the character at an offset of
- Calculate the next index position based on the row and whether itโs the first row or not:
- If itโs the first row or the last row, move by
2 * (numRows - 1)
steps. - Otherwise, move by
2 * (numRows - i - 1)
steps.
- If itโs the first row or the last row, move by
Resetting for the Next Row โป๏ธ
- After finishing one row, reset
ind
to the next rowโs starting position (which isi + 1
). - Reset
r
to 0 for the new row.
Return the Result โ
- Return the final result string
ans
.
This approach follows the ZigZag pattern and efficiently constructs the converted string.
Now you can implement this approach in code to solve the ZigZag Conversion problem.