M面经prepare: Shuffle a deck

设计一个shuffle card

用了java. Random Class

package Random;
import java.util.*;

public class Solution {
    static int cardNum = 10;
    public int[] shuffle(int[] cards) {
        //ArrayList<Integer> res = new ArrayList<Integer>();
        Random rnd = new Random();
        for(int i=0; i<cardNum; i++){
            int rand = rnd.nextInt(cardNum-i)+i;
            int temp = cards[i];
            cards[i] = cards[rand];
            cards[rand] = temp;
        }
        return cards;
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Solution sol = new Solution();
        int[] array = new int[cardNum];
        for (int i=0; i<cardNum; i++) array[i] = i;
        int[] res = sol.shuffle(array);
        System.out.println(Arrays.toString(res));
    }

}