codewars069 饥饿游戏：动物园的灾难！

最新推荐文章于 2025-09-12 18:08:49 发布

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最新推荐文章于 2025-09-12 18:08:49 发布

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文章标签： java python

原文链接：https://my.oschina.net/u/553266/blog/1358464

本文介绍了一个基于动物食物链的模拟程序，通过Java实现了一种算法来模拟动物园内动物之间的捕食行为。该程序使用了HashMap来存储每种动物能够捕食的对象，并通过迭代的方式检查并更新动物间的捕食关系。

2019独角兽企业重金招聘Python工程师标准>>>

Instructions 说明

题目的链接

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

Sample Tests 测试样例:

import org.junit.Test;
import static org.junit.Assert.assertArrayEquals;

public class ExampleTest {

  @Test
  public void example() {    
    final String input = "fox,bug,chicken,grass,sheep";
    final String[] expected = 	{
      "fox,bug,chicken,grass,sheep", 
      "chicken eats bug", 
      "fox eats chicken", 
      "sheep eats grass", 
      "fox eats sheep", 
      "fox"};
    assertArrayEquals(expected, Dinglemouse.whoEatsWho(input));
  }

@Test
  public void example2() {    
    final String input = "bear,banana,banana,grass,busker,panda,antelope,giraffe,cow,big-fish,banana,sheep,grass,lion";
    final String[] expected = 	{
      "bear,banana,banana,grass,busker,panda,antelope,giraffe,cow,big-fish,banana,sheep,grass,lion", 
      "sheep eats grass", 
      "bear,banana,banana,grass,busker,panda,antelope,giraffe,cow,big-fish,banana,sheep,lion"};
    assertArrayEquals(expected, Dinglemouse.whoEatsWho(input));
  }

}

Solution 解决方案：

//https://www.codewars.com/kata/5902bc7aba39542b4a00003d/train/java
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Dinglemouse {
	private static Map<String, String> map = new HashMap<String, String>();
	static {
		map.put("antelope", "grass");
		map.put("big-fish", "little-fish");
		map.put("bug", "leaves");
		map.put("bear", "big-fish,bug,chicken,cow,leaves,sheep");
		map.put("chicken", "bug");
		map.put("cow", "grass");
		map.put("fox", "chicken,sheep");
		map.put("giraffe", "leaves");
		map.put("lion", "antelope,cow");
		map.put("panda", "leaves");
		map.put("sheep", "grass");

	}

	private static String canEatLeftOrRight(String subject, String left,
			String right) {
		String result = canEat(subject, left);
		if (result.equals("")) {
			return canEat(subject, right);
		}
		return result;

	}

	private static String canEat(String subject, String object) {

		if (!map.containsKey(subject) || "".equals(object)) {
			return "";
		}
		if (map.get(subject).indexOf(object) != -1) {
			return String.format("%s eats %s", subject, object);
		}
		return "";
	}

	private static StringBuffer reduce(String[] arr, int subject, String left,
			String right, String rule) {
		String target = rule.split(" ")[2];
		int purge = -1;
		if (target.equals(left)) {
			purge = subject - 1;
		}
		if (target.equals(right)) {
			purge = subject + 1;
		}
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < arr.length; i++) {
			if (i != purge) {
				sb.append(arr[i]).append(",");
			}
		}
		int len = sb.length();
		if (sb.charAt(len - 1) == ',') {
			sb.deleteCharAt(len - 1);
		}
		return sb;
	}

	public static String[] whoEatsWho(final String zoo) {
		List<String> list = new ArrayList<String>();
		list.add(zoo);
		StringBuffer sb = new StringBuffer(zoo);
		boolean reduceable = true;
		Label: while (reduceable) {
			String[] arr = sb.toString().split(",");
			if (arr.length < 2) {
				break;
			}
			for (int i = 0; i < arr.length; i++) {
				String subject = arr[i];
				String left = i > 0 ? arr[i - 1] : "";
				String right = i < arr.length - 1 ? arr[i + 1] : "";

				String check = canEatLeftOrRight(subject, left, right);

				if (!check.equals("")) {
					list.add(check);
					sb = reduce(arr, i, left, right, check);
					break;
				}
				if (i == arr.length - 1) {
					reduceable = false;
					break Label;
				}
			}

		}
		list.add(sb.toString());
		return list.toArray(new String[0]);
		// return new String[]{zoo, zoo};
	}

}

转载于:https://my.oschina.net/u/553266/blog/1358464