Original Writeup on seall.dev

Example 1:

Energy Crystals: [1, 2, 3]

Target Energy: 4

Explanation: There are 4 distinct ways to combine the crystals to reach the target energy level of 4:

1 + 1 + 1 + 1
1 + 1 + 2
2 + 2
1 + 3

Example 2:

Energy Crystals: [2, 5, 3, 6]

Target Energy: 10

Explanation: There are 5 distinct ways to combine the crystals to reach the target energy level of 10:

2 + 2 + 2 + 2 + 2
2 + 2 + 6
2 + 3 + 5
2 + 2 + 3 + 3
5 + 5

# Input energy crystals and target energy as strings
from json import loads
energy_crystals = loads(input())  # Input as a string
target_energy = int(input())  # Input as a string

# Write your solution below and make sure to print the number of ways
dp = [0] * (target_energy + 1)
dp[0] = 1

for crystal in energy_crystals:
    for i in range(crystal, target_energy + 1):
        dp[i] += dp[i - crystal]

print(dp[target_energy])

Flag: HTB{3n34gy_m4tr1x_act1v4t3d_w3_4r3_s4v3d!_bcfb78f9805fa846ebb6521640f079ca}