Is there any good way to generate 100,000 unique 13-digit pure numeric strings?

Is there any good way to generate 100,000 unique 13-digit pure numeric strings

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Is there any good way to generate 100,000 unique 13-digit pure numeric strings

Come one by one. Start with 13 zeros and add 1 at a time. . .

Can be generated by timestamp, or followed by a random number

<code>package com.xtl.demo;

import java.util.HashSet;
import java.util.Random;
import java.util.Set;

/**
 * 生成20组不重复的13位数随机数
 * @author xiatianlong
 *
 * @date 2016年10月8日 上午11:44:57
 */
public class CreatRandomNumber {
    
    
    public static void main(String[] args) {
        Set<String> numberSet = new HashSet<String>();
        
        while(true){
            // 数量大于20条即结束
            if (numberSet.size()>20){
                break;
            }
            String randomNumber = createRandomNumber(13);
            numberSet.add(randomNumber);
        }
        
        for (String string : numberSet) {
            System.out.println(string);
        }
    }
    
    /**
     * 生成指定位数的随机数
     * @param length
     *             生成的位数
     * @return
     */
    public static String createRandomNumber(int length){
        String number ="";
        for (int i = 0; i<length; i++){
            int randomNumber = new Random().nextInt(10);
            number += randomNumber+"";
        }
        return number;
    }
}
</code>

I didn’t think much about performance. . .

You can encrypt any number of characters in one direction and add salt, just 13 bits.

Available in

python random.sample:

<code>random.sample(range(10**12, 10**13), 10**5)
</code>

python2 uses xrange, if you want to start from scratch use format.