Concatenation of Zig-Zag String in ‘n’ Rows
Submissions: 4765   Accuracy:

23.76%

  Difficulty: Medium   Marks: 4

Input:

Given a string and number of rows ‘n’. Print the string formed by concatenating n rows when input string is written in row-wise Zig-Zag fashion.

Examples:

Input: str = "ABCDEFGH"
       n = 2
Output: "ACEGBDFH"
Explanation: Let us write input string in Zig-Zag fashion
             in 2 rows.
A   C   E   G   
  B   D   F   H
Now concatenate the two rows and ignore spaces 
in every row. We get "ACEGBDFH"

Input: str = "GEEKSFORGEEKS"
       n = 3
Output: GSGSEKFREKEOE
Explanation: Let us write input string in Zig-Zag fashion
             in 3 rows.
G       S       G       S
  E   K   F   R   E   K
    E       O       E
Now concatenate the two rows and ignore spaces 
in every row. We get "GSGSEKFREKEOE"

 

Input:

The first line of input consists number of the test cases. The description of T test cases is as follows:

The first line of each test case contains the string, and the second line has 'n' the number of rows.


Output:

In each separate line print the string after concatenating n rows in a zig zag form.


Constraints:

1 ≤ T ≤ 70
1 ≤ N ≤ size of string


Example:

Input:

2
qrrc
3
rfkqyuqfjkxy
2

Output:

qrcr
rkyqjxfqufky

 

** For More Input/Output Examples Use 'Expected Output' option **

Contributor: Madhur Adlakha
Author: madhuradlakha


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