说出八个字包含三个成语，不难，我来说 20000 个吧

package com.example.chengyuconnect;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.DriverManager;

public class ChengyuConnect {
	static String[] cy = new String[30000];
	static String[] cy1=new String[30000];
	static String[] cy2=new String[30000];

	public static void main(String[] args) {
		getCy();
		splitCy();	
		searchCy();
	}
	
	static void getCy() {
		try {
            File f = new File("F:\\chengyu.txt");
            InputStreamReader reader = new InputStreamReader(new FileInputStream(f),"Unicode"); 
            BufferedReader br = new BufferedReader(reader);
            String line = br.readLine();
            for(int n = 0;line.length()==4;n++) { 
                cy[n] = line;
                line = br.readLine();
            }
		} catch (Exception e) {
            e.printStackTrace();
        } 
	}
	
	static void splitCy() {
		for(int i = 0;i<cy.length && cy[i+1]!=null ;i++) {
			cy1[i] = cy[i].substring(0,2);
			cy2[i] = cy[i].substring(2,4);
		}
	}
	
	static void searchCy() {
		for(int i=0;i<cy.length;i++) 
			for(int j=0;j<cy.length;j++) 
				if(cy2[i] != null && cy1[j] != null && cy2[i].equals(cy1[j]))
					for(int k=0;k<cy.length;k++)
						if(cy2[j] != null && cy1[k] != null && cy2[j].equals(cy1[k]))
							System.out.println(cy[i]+cy[k]);
	}
	
}