title	java
date	2019-12-10 02:06:42 -0800
categories	Java
tags	Java

java.util package

查找数据结构

使用Hash的HashTable、HashMap都具有很高效的查找效率

• java.util.HashMap
• java.util.HashTable

HashTable<String, Double> class_prob = new HashTable<String, Double>();
HashTable<Map<String, Double>, Double> class_term_prob = new HashTable<Map<String, Double>, Double>();
class_prob.put(classname, Double.valueOf(args[1])/file_total);
prob = class_prob.getOrDefault(classname, defaultValue: 0.0);

Map<String,String> map = new HashMap<String, String>();
map.put(classname,term);
class_term_prob.put(map, (count+1)/(class_term_total.get(classname)+class_term_num.get(classname)));

• java.util.Map

for(String word:words){
    Map<String,String> map = new HashMap<String, String>();
    map.put(classname, word);
    result += Math.log(class_term_prob.getOrDefault(map,1.0/(class_term_total.get(classname)+class_term_num.get(classname))));
}