help with algorithm

Question

Can you help me to understand this code ?
https://rosettacode.org/wiki/Color_quantization/C
This is code purposed for color quantization, but it's hard to understand pure C, so I can't say in which exactly way it's works. it would great if you explain how it's works c:

Answer 1

C lang work with structured algorithms. Concepts on control & data structures may help