CodeWars 刷题总结

CodeWars

The Hunger Games - Zoo Disaster!

Story

A freak power outage at the zoo has caused all of the electric cage doors to malfunction and swing open...

All the animals are out and some of them are eating each other!

It's a Zoo Disaster!

Here is a list of zoo animals, and what they can eat

antelope eats grass
big-fish eats little-fish
bug eats leaves
bear eats big-fish
bear eats bug
bear eats chicken
bear eats cow
bear eats leaves
bear eats sheep
chicken eats bug
cow eats grass
fox eats chicken
fox eats sheep
giraffe eats leaves
lion eats antelope
lion eats cow
panda eats leaves
sheep eats grass
Kata Task

INPUT

A comma-separated string representing all the things at the zoo

TASK

Figure out who eats who until no more eating is possible.

OUTPUT

A list of strings (refer to the example below) where:

The first element is the initial zoo (same as INPUT)
The last element is a comma-separated string of what the zoo looks like when all the eating has finished
All other elements (2nd to last-1) are of the form X eats Y describing what happened
Notes

Animals can only eat things beside them
Animals always eat to their LEFT before eating to their RIGHT
Always the LEFTMOST animal capable of eating will eat before any others
Any other things you may find at the zoo (which are not listed above) do not eat anything and are not edible
Example

INPUT   
"fox,bug,chicken,grass,sheep"
1   fox can't eat bug   
"fox,bug,chicken,grass,sheep"
2   bug can't eat anything  
"fox,bug,chicken,grass,sheep"
3   chicken eats bug    
"fox,chicken,grass,sheep"
4   fox eats chicken    
"fox,grass,sheep"
5   fox can't eat grass 
"fox,grass,sheep"
6   grass can't eat anything    
"fox,grass,sheep"
7   sheep eats grass    
"fox,sheep"
8   fox eats sheep  
"fox"
OUTPUT  
["fox,bug,chicken,grass,sheep", "chicken eats bug", "fox eats chicken", "sheep eats grass", "fox eats sheep", "fox"]

知识点

• 这个题目比较有意思，主要需要注意的就是先吃左面再吃右面，还有当处理第一个和最后一个动物时需要注意，只能吃右面或者左面。还有个需要注意的是吃掉左面的时候，把左面的元素删掉的时候需要重新判断删除的前一个动物和吃东西的动物之间的关系。