java - Random numbers without duplicate -

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this question has answer here:

public class startorder {   public static void main(string[] args) { int[] start = new int[45];  for(int i=0;i<start.length;i++) {     start[i] = (int)(math.random()*45); }  for(int i=0;i<start.length;i++) {     system.out.println(start[i]); } }  }

i want make simple program prints random numbers between 1-45. problem though there's duplicate numbers among them, how can make print numbers between 1-45 without duplication. it's program generates random start number.

fill list preferred numbers, shuffle it, example using build in library function below.

list<integer> mynumbers = arrays.aslist(1,2,3,4, etc.); collections.shuffle(mynumbers);

then iterate on list.

btw, called random permutation.


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