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Rustower

This repository contains:

• The problem statement of a challenge inspired by Google Hashcode
• Input/Output validator and score-calculator reference implementation (in Rust)
• Input files
• Simple solver and input parser/output dumper (Python)
• Code for generating input files.

Input Files are still WIP

Problem Statement

Compute the best towers to build in order to defend against waves of units given a budget.

Input File

Note: lines starting with '#' are comments, input files do not contain comments

All numbers are integers

UNITS TOWERS WAVES BUDGET

# how many of each unit type a single tower of type 0 can stop
HIT_1 HIT_2 ... HIT_U
# how many of each unit type a single tower of type 1 can stop
...
# how many of each unit type a single tower of type T can stop
...

# cost for each tower
COST_1 COST_2 ... COST_T

# bonuses for each wave
BONUS_1 BONUS_2 ... BONUS_W

# wave 1, number of each unit
N_1 N_2 ... N_U
# wave 2, number of each unit
...
# wave W, number of each unit
...

Constraints

• 0 < UNITS <= 10000
• 0 < TOWERS <= 10000
• 0 < WAVES <= 10000
• 0 < BUDGET <= 10000

Solution/Output File

Note: lines starting with '#' are comments, output files do not contain comments

Output file must contain exactly WAVES lines.

Each line must contain exactly TOWERS integers.

# wave 1 towers of each type
T_1 T_2 ... T_T
# wave 2 towers of each type
...
# wave W towers of each type
...

Scoring

• 1 point for each unit stopped
• for each wave: bonus wave points if all units were stopped

Simulation

For each type of unit, compute how many units of this type towers can stop:

• given a unit i
• T towers

The number of units of type i stopped is sum of N_k * HIT_k_i for k in 0..T-1 where

• N_k is the number of towers of type k.
• HIT_k_i is the number of units of type i a single tower of type k can stop.

Example

Input File

2 2 2 12
2 1
1 2
3 4
2 1
1 1
3 3

2 UNITS, 2 TOWERS, 2 WAVES, BUDGET = 12

1 TOWER of type 0 can stop 2 units of type 0 and 1 unit of type 1

1 TOWER of type 1 can stop 1 unit of type 0 and 2 units of type 1

TOWER 0 costs 3, TOWER 1 costs 4

WAVE 0 bonus is 2, WAVE 1 bonus is 1

WAVE 0 consists of 1 unit of type 0 and 1 unit of type 1

WAVE 1 consists of 3 unit of type 0 and 3 units of type 1

Output File

1 0
0 2

WAVE 1: 1 tower of type 0 and 0 tower of type 1

WAVE 2: 0 tower of type 0 and 2 towers of type 1

total cost = 1 * 3 + 2 * 4 = 11 < 12 (BUDGET)

First wave:

• units of type 0 stopped = 1 (number of towers of type 0) * 2 + 0 (number of towers of type 1) * 1 = 2
• units of type 1 stopped = 1 (number of towers of type 0) * 1 + 0 (number of towers of type 1) * 2 = 1

All units were stopped, score = 1 + 1 (units stopped) + 2 (bonus) = 4

Second wave:

• units of type 0 stopped = 2 (number of towers of type 0) * 2 + 2 (number of towers of type 1) * 1 = 2
• units of type 1 stopped = 0 (number of towers of type 0) * 1 + 2 (number of towers of type 1) * 2 = 4

score = 2 + 3 (4 units of type 1 can be stopped but second wave only has 3 units of type 1) + 0 (no bonus since only 2 units of type 0 out of 3 were stopped) = 5

total score = 4 + 5 = 9

Validate and Compute Score

example:

cargo run --release -- example/input_example.txt example/output_example.txt

example output:

score: 9