Solutions to three interesting problems.

Prolem #3:

#3 - Following the pointers

You are given a puzzle which contains N locations. From each location, you can travel to a maximum of one other location on the puzzle or to a dead end. Your job is to write a program to count how many cycles exist in the puzzle. To clarify, a cycle exists if you can start at a given location and, following the available moves from that location, eventually end up back where you started.

The input your program will be given will be a simplification of the puzzle. The first line of input will indicate how many locations there are in the puzzle, call it N as above. The next N lines show connections between locations. In particular, if line I contains number J, then from location I you can get to location J and only location J. Any location that is a dead end will contain the integer -1. Note that the locations are numbered from 0 to N-1.

Example puzzle:
 

For example, consider the following input:
***
7
2
3
4
5
6
-1
0
***
Then the output of your program should be:
***
1
***

Problem #4:

#4 – String Manipulation

Write a function to compact a string in place: 
A.	strip whitespace from the string.
B.	remove duplicate characters if they are next to each other

For example, consider the following input:
***
abb cddpddef gh
***

Then the output of your program should be:
***
abcdpdefgh
***

Problem #5:

#5 - Spiral printing

Write a function to print a 2-D array (n x m) in spiral order (clockwise).

For example, consider the following input:
***
1 2 3 
4 5 6         
7 8 9 
***

Then the output of your program should be:
***
1 2 3 6 9 8 7 4 5
***