Java 我怎样才能打乱一个单词的字母？
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How can I shuffle the letters of a word?
提问by morgothraud
What is the easiest way to shuffle the letters of a word which is in an array? I have some words in an array and I choose randomly a word but I also want to shuffle the letters of it.
打乱数组中单词的字母的最简单方法是什么？我在数组中有一些单词，我随机选择一个单词，但我也想对它的字母进行洗牌。
public static void main (String[] args ) {
String [] animals = { "Dog" , "Cat" , "Dino" } ;
Random random = new Random();
String word = animals [random.nextInt(animals.length)];
System.out.println ( word ) ;
//I Simply want to shuffle the letters of word
}
I am not supposed to use that List thing. I've come up with something like this but with this code it prints random letters it doesn't shuffle. Maybe I can code something like do not print if that letter already printed?
我不应该使用那个 List 的东西。我想出了这样的东西，但是使用此代码，它会打印不会随机播放的随机字母。也许我可以编写一些代码，例如如果那封信已经打印，则不要打印？
//GET RANDOM LETTER
for (int i = 0; i< word.length(); i++ ) {
char c = (word.charAt(random.nextInt(word.length())));
System.out.print(c); }
}
采纳答案by Rastikan
Really no need for collection and anything more than what follows:
真的不需要收集以及以下内容：
public static void main(String[] args) {
// Create a random object
Random r = new Random();
String word = "Animals";
System.out.println("Before: " + word );
word = scramble( r, word );
System.out.println("After : " + word );
}
public static String scramble( Random random, String inputString )
{
// Convert your string into a simple char array:
char a[] = inputString.toCharArray();
// Scramble the letters using the standard Fisher-Yates shuffle,
for( int i=0 ; i<a.length ; i++ )
{
int j = random.nextInt(a.length);
// Swap letters
char temp = a[i]; a[i] = a[j]; a[j] = temp;
}
return new String( a );
}
回答by Alexis C.
You can use Collections.shuffle:
您可以使用Collections.shuffle：
List<Character> l = new ArrayList<>();
for(char c : word.toCharArray()) //for each char of the word selectionned, put it in a list
l.add(c);
Collections.shuffle(l); //shuffle the list
StringBuilder sb = new StringBuilder(); //now rebuild the word
for(char c : l)
sb.append(c);
word = sb.toString();
I am not supposed to use that List thing.
我不应该使用那个 List 的东西。
Then you can create two StringBuilderobjects. One will hold the original word and one will create the shuffled one :
然后你可以创建两个StringBuilder对象。一个将保留原始单词，另一个将创建洗牌的单词：
StringBuilder s = new StringBuilder(word);
StringBuilder wordShuffled = new StringBuilder();
while(s.length() != 0){
int index = random.nextInt(s.length());
char c = s.charAt(index);
wordShuffled.append(c);
s.deleteCharAt(index);
}
System.out.println(wordShuffled.toString());
I found something like deleteCharAt but I guess it works with StringBuilder or something. I cannot use that
我发现了类似 deleteCharAt 的东西，但我想它适用于 StringBuilder 或其他东西。我不能用那个
Hereyou can find some nice utilities methods that permits to shuffle an array.
在这里，您可以找到一些不错的实用程序方法，它们允许对数组进行洗牌。
public static char[] shuffleArray(char[] x) {
for ( int i = x.length; i > 0; i-- ) {
int rand = (int)(Math.random()*(i));
char temp = x[i-1];
x[i-1] = x[rand];
x[rand] = temp;
}
return x;
}
Then just call this method and use the constructor String(char[] value):
然后只需调用此方法并使用构造函数String(char[] value)：
System.out.println(new String(shuffleArray(word.toCharArray())));
Next time clearly state, what you can use/not use.
下次明确说明，您可以使用/不使用什么。
回答by Elliott Frisch
How about something like this?
这样的事情怎么样？
// Shuffle an array of characters.
public static void shuffleArray(char[] a) {
int n = a.length; // the length of the array.
for (int i = 0; i < n; i++) {
int t = random.nextInt(n); // pick a random number 0 - the length.
if (t == i) { // if the random number is the loop counter
if (i > 0) { // check if we're at the first element.
t = random.nextInt(i); // pick another number between 0 - and the loop counter.
} else {
t = a.length - 1; // the end of the loop.
}
}
a[i] ^= a[t]; // swap a[i] and a[t]
a[t] ^= a[i];
a[i] ^= a[t];
}
}
private static Random random = new Random(); // the shared random.
public static void main(String[] args) {
String[] animals = { "Dog", "Cat", "Dino" };
String word = animals[random
.nextInt(animals.length)];
System.out.println(word); // the random word.
char[] arr = word.toCharArray(); // the char[] from the word.
shuffleArray(arr); // shuffle it.
System.out.println(new String(arr)); // print it.
}
