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52 changes: 26 additions & 26 deletions README.md
Original file line number Diff line number Diff line change
@@ -1,15 +1,15 @@
# Recursion Problems

## Definitions
Define the following:
Define the following:

- Recursion
- Recursive Case
- Base Case
- Activation Chain/Stack
- Activation Record/Call
- Infinite Recursion/Stack Overflow/Stack too deep
- Tail Recursion
- Recursion: method calling itself.
- Recursive Case: a case that would cause the method to run itself
- Base Case: the case that would cause the method to stop
- Activation Chain/Stack: how the recursive method goes to the base case

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Hmm... this definition seems weird to me. Perhaps, "it traces each method call as it gets to the base case"

- Activation Record/Call: each time the recursive method happens
- Infinite Recursion/Stack Overflow/Stack too deep: when base case is never reached
- Tail Recursion: instance where the recursive call is the very last thing in the function

## Tracing through a recursive method

Expand All @@ -24,9 +24,9 @@ def mystery1(n)
end
```

- What is mystery1(5)?
- What is mystery1(10)?
- What is mystery1(0)?
- What is mystery1(5)? 15
- What is mystery1(10)? 55
- What is mystery1(0)? too deep error

### Trace #2
```
Expand All @@ -39,9 +39,9 @@ def mystery2(n)
end
```

- What is mystery2(123)?
- What is mystery2(9005)?
- What is mystery2(-123)?
- What is mystery2(123)? 6
- What is mystery2(9005)? 14
- What is mystery2(-123)? -123
- _Added Fun: How could we make `mystery2(-123)` work the way we might expect it to work instead of the way it does?_

### Trace #3
Expand All @@ -60,9 +60,9 @@ def mystery3(n)
end
```

- What is mystery3(1)?
- What is mystery3(13)?
- What is mystery3(-6)?
- What is mystery3(1)? 100
- What is mystery3(13)? 100
- What is mystery3(-6)? 200

### Trace #4
```
Expand All @@ -75,9 +75,9 @@ def mystery4(b,e)
end
```

- What is mystery4(10,2)?
- What is mystery4(4,3)?
- What is mystery4(5,0)?
- What is mystery4(10,2)100
- What is mystery4(4,3)? 64
- What is mystery4(5,0)?1

### Trace #5
```
Expand All @@ -90,9 +90,9 @@ def mystery5(s)
end
```

- What is mystery5("hi")?
- What is mystery5("")?
- What is mystery5("Hi, there!")?
- What is mystery5("hi")? **
- What is mystery5("")? ""
- What is mystery5("Hi, there!")? **********
- _Added Fun: How could we make only alphabetic characters to be changed to stars?_

### Trace #6
Expand All @@ -110,7 +110,7 @@ def mystery6(s)
end
```

- What is mystery6("goodnight moon")?
- What is mystery6("Ada Developers Academy")?
- What is mystery6("Hi, there!")?
- What is mystery6("goodnight moon")? "moon goodnight"
- What is mystery6("Ada Developers Academy")? "academy developers ada"
- What is mystery6("Hi, there!")? "there! hi"

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Minor error, but notable: there should be a leading space on each of the answers " moon goodnight", " academy developers ada", " there! hi,"

- _Added Fun: How could we make the reversal happen by letter, instead of by word (i.e. Make it so that mystery6("goodnight moon") returned "noom thgindoog")?_