1. Calculate n!
Multiply my number by the factorial of the rest of the numbers.
if( num > 2 )
return num * factorialR2( num - 1 );
else
return 2;

2. Print a string backwards
Print the last character
Print the rest of the string backwards
System.out.print( str.charAt( str.length() - 1 ) );
if( str.length() > 1 )
reverse( str.substring( 0, str.length() - 1 ) );

3. Binary Search Calculate mid-point of the range
Is the value at mid-point the one you're looking for?
If search value < value at mid-point search the low half else search the high half

4. Towers of Hanoi 1. Move n-1 disks from the source to the spare.
2. Move 1 disk from the source to the destination.
3. Move n-1 disks from the spare to the source.

5. Search a directory structure for a file
Loop through the files in this directory
If a listing is itself a directory, search that directory