카카오신입공채 코딩테스트 1차(JAVA)

KakaoTest3.java

package com.jacknie.doodle.kakao;

import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.function.Supplier;

public class KakaoTest3 {

	public static void main(String[] args) {
		int t1 = getRunningTime(3, new String[] {"Jeju", "Pangyo", "Seoul", "NewYork", "LA", "Jeju", "Pangyo", "Seoul", "NewYork", "LA"});
		int t2 = getRunningTime(3, new String[] {"Jeju", "Pangyo", "Seoul", "Jeju", "Pangyo", "Seoul", "Jeju", "Pangyo", "Seoul"});
		int t3 = getRunningTime(2, new String[] {"Jeju", "Pangyo", "Seoul", "NewYork", "LA", "SanFrancisco", "Seoul", "Rome", "Paris", "Jeju", "NewYork", "Rome"});
		int t4 = getRunningTime(5, new String[] {"Jeju", "Pangyo", "Seoul", "NewYork", "LA", "SanFrancisco", "Seoul", "Rome", "Paris", "Jeju", "NewYork", "Rome"});
		int t5 = getRunningTime(2, new String[] {"Jeju", "Pangyo", "NewYork", "newyork"});
		int t6 = getRunningTime(0, new String[] {"Jeju", "Pangyo", "Seoul", "NewYork", "LA"});
		System.out.println(Arrays.asList(t1, t2, t3, t4, t5, t6));
	}

	static int getRunningTime(int cacheSize, String[] cities) {
		
		LruCache cache = new LruCache(cacheSize);
		for (String city : cities) {
			cache.get(city, Object::new);
		}
				
		return cache.getHitCount() + (cache.getMissCount() * 5);
	}
	
	static class LruCache {
		
		private final LinkedHashMap<String, Object> map;
		private final int cacheSize;
		
		private int hitCount;
		private int missCount;
		
		public LruCache(int cacheSize) {
			this.map = new LinkedHashMap<>();
			this.cacheSize = cacheSize;
		}

		public Object get(String key, Supplier<Object> contentsSupplier) {
			key = key.toUpperCase();
			Object value = map.get(key);
			if (value == null) {
				missCount++;
				value = contentsSupplier.get();
				map.put(key, value);
				while (map.size() > cacheSize) {
					String deleteKey = map.keySet().iterator().next();
					map.remove(deleteKey);
				}
				return value;
			}
			else {
				hitCount++;
				return value;
			}
		}

		public int getHitCount() {
			return hitCount;
		}

		public int getMissCount() {
			return missCount;
		}
	}
}