The problem of random number generation in Java

"Generate random number sequence"

We can only use the Math.random () method to generate only a double type floating-point number between [0,1].

But what if we want to generate a random integer between [min, Max]?

At this point you can use:

int rdmnum = (int) (Math.random () * (max + 1-min) + min);

"Random number generator (duplicate random number Present)"

 public  static  int  [] Createrandomarray (int  arrlength, int  Rdmmin, int   Rdmmax) {
//based on the given array length, generate the desired array 
    int  [] arr = new  int  [arrlength"; 
 Assigns a random value to an array  for  (int  i = 0; i < Arr.le Ngth; I++) {Arr[i]  = (int ) (Math.random () * (RDM    Max + 1-rdmmin) + rdmmin); 
//returns this array  return   arr;  

"No repetition of the random number generator (more than 100,000 elements, the more strenuous.) This production device is relatively dead, the range is [0,length] between the number of) "

 Public Static int[] Createrandomnorepeatarray (intlength) {Random RDM=NewRandom (); //Random number Array    int[] arr =New int[length]; //storing an ordered set of numberslist<integer> list =NewArraylist<integer>(); //Random Index    intindex = 0;  for(inti = 0; i < length; i++) {list.add (i); }     for(inti = 0; i < length; i++) {Index= Rdm.nextint (Length-i); Arr[i]=List.get (index);    List.remove (index); }    returnarr;}

The problem of random number generation in Java