【算法】随机排序

shuffle.java

/**
  *  思想：随机交换
  * 
  * @param arr
  */
public static void shuffle(int[] arr) {
    Random r = new Random();
    int size = arr.length;
    for (int i = size; i > 1; i--) {
        int random = r.nextInt(i);

        int temp = arr[i - 1];
        arr[i - 1] = arr[random];
        arr[random] = temp;
    }
}