Explanation of one of the student: (.+) means1 or more of any character \1 means a repetition of what was found in group number1

Question

https://code.sololearn.com/cg09m5in8LuK/?ref=app

Answer 1

Correct, so what is the doubt?

Second group (.+) accepts space, if you want match1 as well

Regex will be ‘(.+)(.+)\1’

Answer 2

Thank you for this explanation. The way the lesson "explains" is not clear at all. Here's what the lessons says:"a backslash and a number between 1 and 99, e.g., \1 or \17. This matches the expression of the group of that number."

Completely impossible to understand, until you explained "\1 means a repetition of what was found in group number 1".