我需要随机洗牌以下数组:
int[] solutionArray = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1};
有什么函数可以做到吗?
我需要随机洗牌以下数组:
int[] solutionArray = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1};
有什么函数可以做到吗?
当前回答
无随机解:
static void randomArrTimest(int[] some){
long startTime = System.currentTimeMillis();
for (int i = 0; i < some.length; i++) {
long indexToSwap = startTime%(i+1);
long tmp = some[(int) indexToSwap];
some[(int) indexToSwap] = some[i];
some[i] = (int) tmp;
}
System.out.println(Arrays.toString(some));
}
其他回答
类似的情况没有使用swap b
Random r = new Random();
int n = solutionArray.length;
List<Integer> arr = Arrays.stream(solutionArray)
.boxed()
.collect(Collectors.toList());
for (int i = 0; i < n-1; i++) {
solutionArray[i] = arr.remove(r.nextInt(arr.size())); // randomize based on size
}
solutionArray[n-1] = arr.get(0);
你现在可以使用java 8了:
Collections.addAll(list, arr);
Collections.shuffle(list);
cardsList.toArray(arr);
下面是使用集合的完整解决方案。洗牌的方法:
public static void shuffleArray(int[] array) {
List<Integer> list = new ArrayList<>();
for (int i : array) {
list.add(i);
}
Collections.shuffle(list);
for (int i = 0; i < list.size(); i++) {
array[i] = list.get(i);
}
}
请注意,由于Java无法在int[]和Integer[]之间平滑转换(因此int[]和List<Integer>),它受到了影响。
你应该使用Collections.shuffle()。但是,不能直接操作原始类型数组,因此需要创建包装器类。
试试这个。
public static void shuffle(int[] array) {
Collections.shuffle(new AbstractList<Integer>() {
@Override public Integer get(int index) { return array[index]; }
@Override public int size() { return array.length; }
@Override public Integer set(int index, Integer element) {
int result = array[index];
array[index] = element;
return result;
}
});
}
And
int[] solutionArray = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1};
shuffle(solutionArray);
System.out.println(Arrays.toString(solutionArray));
输出:
[3, 3, 4, 1, 6, 2, 2, 1, 5, 6, 5, 4]
最简单的解决方案,这种随机洗牌数组。
String location[] = {"delhi","banglore","mathura","lucknow","chandigarh","mumbai"};
int index;
String temp;
Random random = new Random();
for(int i=1;i<location.length;i++)
{
index = random.nextInt(i+1);
temp = location[index];
location[index] = location[i];
location[i] = temp;
System.out.println("Location Based On Random Values :"+location[i]);
}