玩玩小程序

一、L的3.41次方+40000L的1.56次方=21780889，帮我算出L

解决方案，正常算，确实不会算，采用无限趋近法，得到近似值，编程采用递归

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.Console;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.List;


public class Io {
	
	public static void main(String args[]) throws Exception{
		new Io().operate(1, 1000, 1);
		
		}
		
		private void operate(double min,double max,double add){
			boolean bool = true;
			List<Double> list = new ArrayList<Double>();
			List<Double> listSub = new ArrayList<Double>();
			double sub = 0;
			for(double i=min;i<max;i+=add){
				list.add(i);
				double result = Math.pow(i, 3.41) + Math.pow(i, 1.56)*40000;
				if((sub = Math.abs(result-21780889)) < 0.001){
					bool = false;
					break;
				}else{
					listSub.add(sub);
				}
			}
			if(bool){
				int pos = 0;
				for(int j=0;j<listSub.size()-1;j++){
					pos = j;
					if(listSub.get(j)<listSub.get(j+1)){
						break;
					}
				}
				operate(list.get(pos-1), list.get(pos+1), add/10);
			}else{
				System.out.println("最终结果："+list.get(list.size()-1)+"    "+sub);
			}
		}
}

 

二、

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.Console;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.List;


public class Io {
	
	public static void main(String args[]) throws Exception{


		String path = "c:\\weibo.txt";
		String content = null;
		String account[];
		
		//read the txt;
		content = new Io().readTxt(path);
		
		// show all of the accounts on the screen
		account = content.split("#");
		for(int i=0,len=account.length;i<len;i++){
			System.out.println(account[i]);
		}
		
		// " " replace # and save in the floder
		content = content.replace("#", " ");
		new Io().writeTxt("c:\\chulihou.txt", content);  //chulihou.txt这出题人也够NB嗒
		
		//delete the floder
		File file = new File(path);
		file.delete();
	}
	
	private String readTxt(String path) throws Exception{
		StringBuffer string = new StringBuffer();
		String temp;
		BufferedReader in =new BufferedReader(new FileReader(path));
		while((temp = in.readLine()) != null){
			string.append(temp);
		}
		in.close();
		return string.toString();
	}
	
	private void writeTxt(String path, String content) throws Exception{
		FileWriter   fw=new   FileWriter( path ); 
		BufferedWriter   bw   =new   BufferedWriter(fw); 
		bw.write( content );
		bw.flush();
		bw.close();
		fw.close();
	}

}