Problem 2601. Concatenate string with cell array of strings

Given a cell array of strings (a), a target string (b), and a target position (ind), return a cell array of strings (c) in which the target string has been inserted starting at the target position in each of the cells.

Assumptions

• ind is a scalar
• ind > 0
• ind <= (minimum length of a string in a) + 1

Example

If

a = {'filename1';
     'filename2';
     'filename3'};
b = '_';
ind = 9;

Then

c = {'filename_1';
     'filename_2';
     'filename_3'};