Generate questions randomly and non repaeted from the xml file in android

Question

I have a xml file having 50 different questions and i need only 15 out of them randomly and non-repeated.I used the code below

int n = ((int)(Math.random()*100))%50;
if(temp<15)
{
    for(int i=0;i<temp;i++)
    {
        System.out.println("hello naresh");
        if(n==check[i])
        {
            n=((int)(Math.random()*100))%50;
        }
    }
    check[temp]=n;
}

temp++;
return n;

But by using this some questions are repeated.Please suggest me something which help me to generate the non-repeated questions.

use following [link](http://stackoverflow.com/a/4040014/491978) for generating random numbers. — Mihir Palkhiwala, Feb 06 '12 at 06:29

score 1 · Accepted Answer · answered Apr 12 '12 at 04:19

By this way u can generate any no of random no.

     int max=50;
        List<Integer> indices;
    int randomIndex = 0;
random(){
    int arrIndex = (int)((double)indices.size() * Math.random());
           System.out.println("my random no is:"+arrIndex);
           randomIndex = indices.get(arrIndex);
           indices.remove(arrIndex);
            return randomIndex;
}

score 1 · Answer 2 · answered Feb 06 '12 at 07:07

Shuffle the numbers 0,1,...49 and take the first 15 numbers:

ArrayList<Integer> indices = new ArrayList<Integer>();
for (int i = 0; i < 50; i++)
  indices.add(i);

Collections.shuffle(indices);
List<Integer> random15 = indices.subList(0,15);

It also shuffles the other 35 numbers, a bit of unnecessary work, but for such small numbers it's not a problem.

Generate questions randomly and non repaeted from the xml file in android

2 Answers2