app.java

数据结构 包括数组(Array包) 和二叉树(Tree) 链表(Linelist包) 等等

package MyLib;
import java.util.*;
import java.io.*;
public class App {
  static	Random rn;
  static	BufferedReader br;
  static	InputStreamReader in;
  static 	String s;
	public App(){
		 
		
	}
	
	public static int nextInt(int start,int end){
		rn=new Random();
		return (start+rn.nextInt(end));
	}
	
    public static String randomString(int size,int rangStart,int rangEnd){
    	rn=new Random();
    	char[] ch=new char[size];
    	char chUnit;
    	for(int i=0;i<ch.length;i++){
    		chUnit=(char)(rangStart+rn.nextInt(rangEnd));
    		ch[i]=chUnit;
    	}
    	String result=new String(ch);
    	return result;
    }
    
	public static String readString() throws IOException{
		in=new InputStreamReader(System.in);
		 br=new BufferedReader(in);
	   s =br.readLine();

	    return s;
	    
	
	}
	
	public static int readInt() {
		int result=0;
		in=new InputStreamReader(System.in);
		 br=new BufferedReader(in);
		enter: while(true){
	       try{
		       s=br.readLine();
		         while(s.matches("[^0-9]")){
			    System.out.println("please enter a number");
			     s=br.readLine();
		       }
		        result=Integer.parseInt(s);    
		        break;
		       }catch(IOException e){
			      e.printStackTrace();
		       }catch(NumberFormatException ex){
		    	   System.out.println("please enter correct number format");
		    	   continue enter;
		       }
		 }
      return result;
	
	}
	
}