Swap Ends - codepath/compsci_guides GitHub Wiki

Unit 3 Session 1 (Click for link to problem statements)

U-nderstand

Understand what the interviewer is asking for by using test cases and questions about the problem.

• Will the string ever be empty?
  • Potentially, yes. Your code should allow for this.

P-lan

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Slice the input string into three components and then combine them at the end.

1) Slice the last character from the input string
2) Slice the middle (excluding the first and last) characters from the input string
3) Slice the first character from the input string
4) Return these three components added together in the order: last, middle, first

I-mplement

def swap_ends(myStr):
    return myStr[-1:] + myStr[1:-1] + myStr[:1]