anton-kotik / php-interview

A courier on a motorcycle is delivering packages. There are several delivery orders: A, B, C, etc. Each order consists of two points (addresses). For each order, the courier should pick up the parcel at the first address (B1) and deliver it to the second address (B2).

The route time in minutes between all points and the courier is specified in the file. For example, for data2.txt file, the travel time from the courier (CR) to point B1 is 14 minutes, and from point B2 to the courier (CR) is 53 minutes.

   CR A1 A2 B1 B2 C1 C2
CR  0 97 36 14 52 59 89
A1 94  0 68 14 63 25 30
A2 38 65  0 20 20 56 82
B1 13 14 20  0 56  4 99
B2 53 58 21 58  0 17 85
C1 61 27 57  4 16  0 84
C2 89 31 79 99 90 78  0

Solve the problems below. Feel free to use Google, StackOverflow, and PHP documentation if needed.
You you don't have to write your own file parser, there's already a FilePaster class in the code.
You can modify the code if needed.

Problem 1

Find the nearest order to the courier. Modify the script problem1.php so that it returns
the name of the point (for example, B1) to which the courier should go to get his first parcel as soon as possible.

php problem1.php data1.txt

Check your solution.

Data file	Command	Expected result
data1.txt	php problem1.php data1.txt	A1
data2.txt	php problem1.php data2.txt	B1
data3.txt	php problem1.php data3.txt	C1

Problem 2

Find the most optimal route to deliver all orders in minimum time.
The courier can carry maximum 2 parcels at the same time.

php problem2.php data1.txt

Modify the problem2.php script so that it returns the route points on the first line
and the total route time on the second line. For example:

A1 B1 B2 A2
175

Check your solution.

Data file	Command	Expected result
data1.txt	php problem2.php data1.txt	Route: A1 B1 B2 A2 Time: 175
data2.txt	php problem2.php data2.txt	Route: B1 C1 B2 A1 C2 A2 Time: 201
data3.txt	php problem2.php data3.txt	Route: C1 C2 A1 A2 B1 B2 Time: 95

If you wish, optimize the code and test your solution on files with large number of orders:

Data file	Command	Expected result
huge1.txt	php problem2.php huge1.txt	Route: F1 F2 D1 E1 E2 D2 C1 B1 C2 A1 B2 A2 Time: 314
huge2.txt	php problem2.php huge2.txt	Route: C1 B1 C2 G1 B2 E1 G2 F1 E2 F2 D1 H1 H2 A1 A2 D2 Time: 340