Java中打乱一个数组的2种公平算法分享

package test.ms;

import java.util.Random;

public class Redistribute2 {
	public static void main(String[] args) {
		
		//define the array 
		int[] s = {1,5,4,3,6,9,8,7,0,8,5,6,7,2};
		
		// before redistribute output
		System.out.println("before redistribute:");
		for(int i = 0 ; i<s.length; i++){
			System.out.print(s[i]+" ");
		}
		
		// invoke the method 
		shuffle(s,new Random());
		
		System.out.println();
		
		// after redistribute output
		System.out.println("after redistribute:");
		for(int i = 0 ; i<s.length; i++){
			System.out.print(s[i]+" ");
		}
	}
  
	// using the random get the random number
	public static  void  shuffle(int[] array, Random random){
		
		for(int i = array.length; i >= 1; i--){
			
			swap(array,i-1,random.nextInt(i));
		}
	}
	
	// the two number swap  in the array
	public static void swap(int[] array, int i , int j){
	 
		int temp = array[i];
		
		array[i] = array[j];
		
		array[j] = temp;
	 
		
	}
}

before redistribute:
1 5 4 3 6 9 8 7 0 8 5 6 7 2 
after redistribute:
9 8 7 8 0 6 1 6 5 5 2 3 7 4 

package test.ms;

import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Random;
import java.util.Set;

public class Redistribute {
	
	public static void main(String[] args) {
		int[] s = {1,5,4,3,6,9,8,7,0,8,5,6,7,2};
		redistribute(s);
	}
	public static void  redistribute(int[] s){
		Random  random = new Random();
		
		Set<Integer> set = new LinkedHashSet<Integer>();
		
		// redistribute the  index
		while(true){
			int t =random.nextInt(s.length);
			set.add(t);
			if(set.size()== s.length)
			break;
		}
		System.out.println("before redistribute:");
		for(int i = 0 ; i<s.length; i++){
			System.out.print(s[i]+" ");
		}
		System.out.println();
		System.out.println("redistribute the index ");System.out.println(set);
		
		int [] out = new int[s.length];
		
		int count = 0;
		
		for(Iterator<Integer> iterator = set.iterator(); iterator.hasNext();){
			out[count] = s[iterator.next()];
			count++;
		}
		
		// out the result;
		System.out.println("after redistribute:");
		for(int i = 0 ; i<s.length; i++){
			System.out.print(out[i]+" ");
		}
	}
	
}

before redistribute:
1 5 4 3 6 9 8 7 0 8 5 6 7 2 
redistribute the index 
[6, 2, 9, 1, 10, 5, 11, 4, 12, 3, 7, 8, 0, 13]
after redistribute:
8 4 8 5 5 9 6 6 7 3 7 0 1 2