Zig-Zag String Problem Statement

Given a string STR of size N and an integer M representing the number of rows in the zig-zag pattern, return the string formed by concatenating all rows when the string STR is written in a row-wise zig-zag pattern.

Example:

Input:

N = 12, M = 3, STR = 'CODINGNINJAS'

Output:

'CNNOIGIJSDNA'

Explanation:

When arranged in a zig-zag pattern with 3 rows, the rows contain the following letters: Row 1: 'CNN', Row 2: 'OIGIJS', Row 3: 'DNA'. Concatenating these rows gives the result: 'CNNOIGIJSDNA'.

Constraints:

1

Question

Zig-Zag String Problem Statement

Given a string STR of size N and an integer M representing the number of rows in the zig-zag pattern, return the string formed by concatenating all rows when the string STR is written in a row-wise zig-zag pattern.

Example:

Input:

N = 12, M = 3, STR = 'CODINGNINJAS'

Output:

'CNNOIGIJSDNA'

Explanation:

When arranged in a zig-zag pattern with 3 rows, the rows contain the following letters: Row 1: 'CNN', Row 2: 'OIGIJS', Row 3: 'DNA'. Concatenating these rows gives the result: 'CNNOIGIJSDNA'.

Constraints:

1 <= T <= 10^2
1 <= N <= 10^3
1 <= M <= N
STR contains only uppercase letters ('A-Z').
Time Limit: 1 second

Accepted Answer

Arrange a string in zig-zag pattern with given number of rows and concatenate the rows.

Iterate through the string and distribute characters to rows based on zig-zag pattern
Concatenate the characters in each row to get the final result
Handle edge cases like when number of rows is 1 or equal to the length of the string