Recursion

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Recursion

• To understand recursion, you have to understand
  recursion
• Nicolas Pelletier

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Recursion calling yourself

• A very powerful way of resolving problems
• Eliminates long and complex solutions
• Revolution in programming
• Dangerous as it can go into an infinite loop
• Can create memory leaks

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The String reverser
This case was easy to solve, so we will use it to
demonstrate recursion
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Here is a new way
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How???

• doIt(Bishops College School)
• return l doIt(Bishops College Schoo)
• return o doIt(Bishops College Scho)
• return o doIt(Bishops College Sch)
• return h doIt(Bishops College Sc)

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Continued
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Other example
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Assignment 10

• Write a recursive method in a class that solves
  the following problem
• The method should order a list of letters (a
  string) from decreasing alphabetical order, from
  z to a
• The list should contain 10-15 letters