Java ， NFA转DFA
文章目录
可以从文件中读取NFA， 也可以在命令行中自己输入NFA的各个值。代码是算法部分。
请读者以学习为主，尽量不要直接复制粘贴运行，因为有些地方不改一下是运行不了的。
全部代码都是自己一点点打的，转载请注明出处，谢谢支持！
import java.awt.List;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeSet;
public class nfatodfa {
private static String chushizhuangtai = null;
public static ArrayList zifuji = new ArrayList<>(); // 字符集
private static ArrayList nfazhuangtai = new ArrayList<>(); // NFA状态集
public static ArrayList jieshuzhuangtai = new ArrayList<>(); // 结束状态集
private static ArrayList zifuhu = new ArrayList<>(); // 字符弧
private static ArrayList konghu = new ArrayList<>(); // 空弧
private static HashMap kongji = new HashMap<>();
public static HashMap dfahanshu = new HashMap<>();
private static String dfachutai = null; // DFA初始状态
public static ArrayList a4 = new ArrayList<>(); //保存dfa每个状态
//这个可以自行修改，本来还有个图形化界面，不过还不成熟，
//就没有放上来
public nfatodfa(String chushizhuangtai2,
ArrayList jieshuzhuangtai1, ArrayList zifuji1,
ArrayList nfazhuangtai1, ArrayList konghu2,
ArrayList zifuhu2) {
// TODO Auto-generated constructor stub
this.chushizhuangtai=chushizhuangtai2;
this.jieshuzhuangtai=jieshuzhuangtai1;
this.zifuji=zifuji1;
this.nfazhuangtai=nfazhuangtai1;
this.konghu=konghu2;
this.zifuhu=zifuhu2;
}
// 从开始状态开始获取下一个DFA函数状态，并保存下来
// s5 初始状态
public static void xhdfahanshu(String s5) {
ArrayList aaaaaa = new ArrayList<>();
String s6 = "";
a4.add(s5);
int i = 0;
while (i != a4.size()) {
int m = a4.size();
String[] si = (String[]) a4.toArray(new String[m]);
for (String zifu : zifuji) { //遍历每一个字符
String s1 = getzifu(si[i], zifu);
for (int j = 0; j < s1.length(); j++) {
char c2 = s1.charAt(j);
String s2 = String.valueOf(c2);
String s3 = kongji.get(s2);
aaaaaa.add(s3);
}
if (!aaaaaa.isEmpty()) {
String s4 = strxiangjia(aaaaaa);
aaaaaa.clear();
if (!a4.contains(s4)) {
a4.add(s4);
}
s6 = si[i].toString();
s6 += ":" + zifu;
dfahanshu.put(s6, s4);
}
}
i++;
}
}
// 把N个集合进行合并
// 每一个value都是一个集合
// 合并后的集合
public static String strxiangjia(ArrayList arr) {
SortedSet sd = new TreeSet<>();
String ss = "";
for (String s : arr) {
for (int i = 0; i < s.length(); i++) {
sd.add(s.charAt(i));
}
}
for (char c : sd) {
ss += c;
}
return ss;
}
//准备工作
// 获取S中每一个状态经过zifu生达到的状态
public static String getzifu(String s, String zifu) {
int i = s.length();
String s1 = "";
for (int j = 0; j < i; j++) {
char c = s.charAt(j);
String ss = String.valueOf(c);
for (String sss : zifuhu) {
if (sss.startsWith(ss) && sss.charAt(1) == zifu.charAt(0)) {
s1 += sss.charAt(2);
}
}
}
return s1;
}
//NFA中的每一个状态经过空弧后到达的状态
public static void KongJi() {
for (String s : nfazhuangtai) {
String sss = "";
tranji.add(s);
Get_ztj(s);
for (String ss : tranji)
sss += ss;
kongji.put(s, sss); // 某一字符经过空弧到达的状态集
tranji.clear();
}
}
// 对每一个状态遍历空弧找到等状态 在110行中使用
private static SortedSet tranji = new TreeSet<>();
public static void Get_ztj(String zt) {
for (String s : konghu) {
if (s.startsWith(zt)) {
tranji.add(s.substring(2));
Get_ztj(s.substring(2));
}
}
}
public static void Get_DfaFirst(String cszt) {
for (String s : konghu) {
if (s.startsWith(cszt)) {
dfachutai += s.substring(2);
Get_DfaFirst(s.substring(2));
}
}
}
public static void GetDfaFirst() {
dfachutai = chushizhuangtai;
Get_DfaFirst(chushizhuangtai);
}
public static void wjGet_Nfa(){
File file = new File("E:/ceshi.txt");
String s =null;
try {
BufferedReader br = new BufferedReader(new FileReader(file));
while((s=br.readLine())!=null){
char c = s.charAt(0);
switch (c) {
case '0':
chushizhuangtai=s.substring(1);
break;
case '1':
jieshuzhuangtai.add(s.substring(1));
break;
case '2':
zifuji.add(s.substring(1));
break;
case '3':
nfazhuangtai.add(s.substring(1));
break;
case '4':
if(s.charAt(2)=='#')
konghu.add(s.substring(1));
else
zifuhu.add(s.substring(1));
break;
default:
break;
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void Get_Nfa() {
System.out.print("输入初始状态：");
Scanner s = new Scanner(System.in);
chushizhuangtai = s.next(); // 初始状态
System.out.println("输入结束状态：");
Scanner sc5 = new Scanner(System.in);
while (true) {
String jieshu = sc5.next();
if (jieshu.equals("over"))
break;
else {
jieshuzhuangtai.add(jieshu);
}
}
System.out.println("输入字符集："); // 字符集
Scanner s1 = new Scanner(System.in);
while (true) {
String ss1 = s1.next();
if (ss1.equals("over")) {
break;
} else {
zifuji.add(ss1);
}
}
System.out.println("输入NFA状态集：");
Scanner s2 = new Scanner(System.in);
while (true) {
String ss2 = s2.next();
if (ss2.equals("over")) {
break;
} else {
nfazhuangtai.add(ss2);
}
}
System.out.println("输入函数集："); // 函数集
Scanner sc = new Scanner(System.in);
while (true) {
String nfa = sc.next();
if (nfa.equals("over"))
break;
else if (nfa.charAt(1) == '#')
konghu.add(nfa);
else
zifuhu.add(nfa);
}
}
//这个本来是主函数，读者可自己修改
public static void zhixing() {
wjGet_Nfa();
GetDfaFirst();
KongJi();
xhdfahanshu(dfachutai);
// new Tuxing(dfahanshu,a4);
System.out.println(konghu);
System.out.println(zifuhu);
System.out.println(dfachutai);
System.out.println(kongji);
System.out.println(dfahanshu);
}
}