请教两道问题？
/*　创建一个整数数组，数组大小随机产生，数组里面的整数也是随机产生的
1-1000之间的整数。*/

//这道题我怎么也不知道应该如何获得随机数，希望大家多多指点，最好加点注释

public   class   suijishu   {
public   static   void   main(String[]   args){
int[]   random   =   new   int[];
for(int   i=0;i <random.length;i++){
random[i]   =   (int)(Math.random()*1000)   +   1;
System.out.print(random[i]   +   "   ");
}
System.out.println();
}
}

/*   编写一个猜数字的程序，先随机产生一个1-100之间的整数，接着请用户输入猜的数字，如果猜大了就显示：“大了！”,猜小了就显示“小了！”，然后继续猜，直到猜对为止。   */

//　这道题如何让它猜对就截止

mport   java.util.Scanner;
public   class   caidaxiao   {
public   static   void   main(String[]   args){
int   i;
int   shu;
int[]   random;
do{
System.out.print( "请输入数字： ");
Scanner   scan   =   new   Scanner(System.in);
shu   =   scan.nextInt();
random   =   new   int[100];
for(i   =   0;i   <   random.length;i++){
random[i]   =   (int)(Math.random()*100)   +   1;
if(shu   <   random[i]){
System.out.println( "小了! ");
break;
}
else   if(shu   >   random[i]){
System.out.println( "大了! ");
break;
}
}
}while(shu   ==   random[i]);
}
}

------解决方案--------------------
让电脑傻一傻也可以....

package sunflowerbbs.oicp.net;

import java.io.*;

public class Guess {
public static void main(String[] args) {
int numGiveByPerson = 0;
String str;
boolean error = true;
while (error)
try {
System.out
.println( "type a num,which between 1 and 1024.Then Let me have a guess! ");
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
str = br.readLine();
numGiveByPerson = Integer.parseInt(str);
if (numGiveByPerson > = 1 && numGiveByPerson <= 1024) {
error = false;
} else
System.out.println( "the num should be between 1 and 1024! ");
} catch (NumberFormatException e) {
System.out.println( "invalid format! ");
} catch (Exception e) {
e.printStackTrace();
}
int top = 1;
int bottom = 1024;
int mid = (top + bottom) / 2;
int s = 1;
do {
System.out.println(mid + "!big or small? ");
try {
str = new BufferedReader(new InputStreamReader(System.in))
.readLine();
if (str.toLowerCase().charAt(0) == 'b ')
bottom = mid - 1;
else
top = mid + 1;
mid = (top + bottom) / 2;
s = s * 2;
if (s > 1024) {
System.out.println( "play a joke on me! I 'll Exit! ");
return;
}
} catch (Exception e) {

}
} while (mid != numGiveByPerson);
System.out.println(mid + "? HaHa... ");
System.out.println( "you are right.how clever you are! ");

}

}

------解决方案--------------------
第一道题：数组大小和数组里的值都是随机的
int n = (int) (Math.random() * 100);
System.out.println(n);
int[] random = new int[n];
for (int i = 0; i < n; i++) {