Is there an easy way to rearrange a number in java? [closed]

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Basically in a nut shell I want to take a random number say:

73524896

and I want to us the same number but randomly rearrange it like this:

46932857

Is there a way I can do t开发者_开发百科his easily in java?

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Here's my favorite solution. (Note that all shufflings are equally probable.)

Random rnd = new Random();
int rndInt = rnd.nextInt(10000000);

String[] rndChars = ("" + rndInt).split("(?<=.)");
Collections.shuffle(Arrays.asList(rndChars));
String result = "";
for (String s : rndChars) result += s;
int shuffled = Integer.parseInt(result);

// Print original and shuffled
System.out.println(rndInt);
System.out.println(shuffled);

Sample output:

4769797
9497767

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//generate random number
String number = "73524896";

//put each digit in an element of a list
List<Character> numberList = new ArrayList<Character>();
for (char c : number.toCharArray()){
  numberList.add(c);
}

//shuffle
Collections.shuffle(numberList);

//output
String shuffledNumber = "";
for (Character c : numberList){
  shuffledNumber += c;
}
System.out.println(shuffledNumber);

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This will this help you : Random Numbers - shuffling.

Not a complete code, just a snippet from the link

Random rgen = new Random();  // Random number generator
int[] cards = new int[52];  

//--- Initialize the array to the ints 0-51
for (int i=0; i<cards.length; i++) {
    cards[i] = i;
}

//--- Shuffle by exchanging each element randomly
for (int i=0; i<cards.length; i++) {
    int randomPosition = rgen.nextInt(cards.length);
    int temp = cards[i];
    cards[i] = cards[randomPosition];
    cards[randomPosition] = temp;
}

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turn it into a string, get the character array, then randomize the character array, and turn it back into a string.

that would let you randomize any string, not just numbers.

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I would say the easiest way to do this is to parse the integer to a String, rearrange the digit in the String then parse it back to integer.

public int rearrange(int num){
  StringBuilder asStr = new StringBuilder(num + ""); //convert to string

  inplaceShuffle(asStr);


  return Integer.parseInt(asStr.toString());

}

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(1) Convert the number to a string

(2) Use a standard shuffling algorithm to shuffle the characters

(3) Convert back to a number

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Collections.shuffle() takes a list and returns a list, which has a toArray(). Arrays.asList() takes an array and returns a list. String has a toCharArray() and a constructor that accepts a char array. Integer has toString() and valueOf()