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
public class ShuffleArray {
public static void shuffleArray(int[] a) {
int n = a.length;
Random random = new Random();
random.nextInt();
for (int i = 0; i < n; i++) {
int change = i + random.nextInt(n - i);
swap(a, i, change);
}
}
private static void swap(int[] a, int i, int change) {
int helper = a[i];
a[i] = a[change];
a[change] = helper;
}
public static void main(String[] args) {
int[] a = new int[] { 1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1 };
shuffleArray(a);
for (int i : a) {
System.out.println(i);
}
}
}
其他回答
使用随机类
public static void randomizeArray(int[] arr) {
Random rGenerator = new Random(); // Create an instance of the random class
for (int i =0; i< arr.length;i++ ) {
//Swap the positions...
int rPosition = rGenerator.nextInt(arr.length); // Generates an integer within the range (Any number from 0 - arr.length)
int temp = arr[i]; // variable temp saves the value of the current array index;
arr[i] = arr[rPosition]; // array at the current position (i) get the value of the random generated
arr[rPosition] = temp; // the array at the position of random generated gets the value of temp
}
for(int i = 0; i<arr.length; i++) {
System.out.print(arr[i]); //Prints out the array
}
}
下面的代码将实现数组的随机排序。
// Shuffle the elements in the array
Collections.shuffle(Arrays.asList(array));
来自:http://www.programcreek.com/2012/02/java-method-to-shuffle-an-int-array-with-random-order/
使用ArrayList<Integer>可以帮助您解决洗牌问题,而无需应用大量逻辑和消耗更少的时间。以下是我的建议:
ArrayList<Integer> x = new ArrayList<Integer>();
for(int i=1; i<=add.length(); i++)
{
x.add(i);
}
Collections.shuffle(x);
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。
看看Collections类,特别是shuffle(…)。