# TASK #1 › Pack a Spiral

## The task

You are given an array `@A`

of items (integers say, but they can be anything).

Your task is to pack that array into an `MxN`

matrix spirally counterclockwise, as tightly as possible. Tightly means the absolute value |M-N| of the difference has to be as small as possible.

## My solution

This challenge is kinda of the reverse of task 2 from challenge 88. In that task we were given a spiral and had to unwind it.

This task can be broken up into three steps:

- Work out the tightest grid.
- Work with
`$y`

from 1 to one less than the array size. - If the array size can be evenly divided by
`$y`

and it is tighter than the current grid size, update`$max_x`

and`$max_y`

.

- Work with
- Populate the grid
- Create a
`@direction`

array with the x/y offsets for right, up, left and down. - Create a loop from 0 to
`$#values`

. - Put that value in the given location.
- If the next x/y value is either out of bounds or that position already has a value, change directions.

- Create a
- Display the grid
- Since 0,0 represents the bottom left, we use the reverse function on the
`@grid`

array. - I use
`sprintf`

to right justify numbers and left justify strings. This ensure that even if the lengths of the values are different, they will be correctly aligned.

- Since 0,0 represents the bottom left, we use the reverse function on the

## Examples

```
» ./ch-1.pl 1 2 3 4 5 6
6 5 4
1 2 3
» ./ch-1.pl 1 2 3 4 5 6 7 8 9 10 11 12
9 8 7 6
10 11 12 5
1 2 3 4
» ./ch-1.pl the quick brown fox jumps over the lazy dog
the over jumps
lazy dog fox
the quick brown
```

# TASK #2 › Origin-containing Triangle

## The task

You are given three points in the plane, as a list of six co-ordinates: `A=(x1,y1)`

, `B=(x2,y2)`

and `C=(x3,y3)`

.

Write a script to find out if the triangle formed by the given three co-ordinates contain origin (0,0).

Print 1 if found otherwise 0.

## My solution

I have debated whether I should submit a solution to this task. I am, but with a massive caveat. My high school algebra was more than 25 years ago, and the **solution is not my own workings**. I've taken the first solution from this website, and convert it to Perl.

## Examples

```
» ./ch-2.pl "A=(0,1), B=(1,0) and C=(2,2)"
0
» ./ch-2.pl "A=(1,1), B=(-1,1) and C=(0,-3)"
1
» ./ch-2.pl "A=(0,1), B=(2,0) and C=(-6,0)"
1
```

## Discussion (0)