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package com.xuyisen.monitor.test;
import java.util.Random;
public class Test {
/**
* 获取count个随机数
* @param count 随机数个数
* @return
*/
public String game(int count){
StringBuffer sb = new StringBuffer();
String str = "0123456789";
Random r = new Random();
for(int i=0;i<count;i++){
int num = r.nextInt(str.length());
sb.append(str.charAt(num));
str = str.replace((str.charAt(num)+""), "");
}
return sb.toString();
}
public static void main(String[] args) {
Test t = new Test();
System.out.println(t.game(4));
}
}
import java.util.Random;
public class RandomTest {
public static void main(String[] args) {
System.out.println(random(4));
}
public static String random(int n) {
if (n < 1 || n > 10) {
throw new IllegalArgumentException("cannot random " + n + " bit number");
}
Random ran = new Random();
if (n == 1) {
return String.valueOf(ran.nextInt(10));
}
int bitField = 0;
char[] chs = new char[n];
for (int i = 0; i < n; i++) {
while(true) {
int k = ran.nextInt(10);
if( (bitField & (1 << k)) == 0) {
bitField |= 1 << k;
chs[i] = (char)(k + '0');
break;
}
}
}
return new String(chs);
}
}
Random ran=new Random();
int r=0;
m1:while(true){
int n=ran.nextInt(10000);
r=n;
int[] bs=new int[4];
for(int i=0;i<bs.length;i++){
bs[i]=n%10;
n/=10;
}
Arrays.sort(bs);
for(int i=1;i<bs.length;i++){
if(bs[i-1]==bs[i]){
continue m1;
}
}
break;
}
System.out.println(r);
List list = new ArrayList();
Random r = new Random();
boolean b = true;
int num;
while (b) {
num = r.nextInt(1000);
if (!list.contains(num)) {
list.add(num);
}
if(list.size() == 100){
b = false;
}
}
System.out.println(Arrays.asList(list));