Scala implementation of scrambled array

 

 

Article Directory

• Preface
• 1. What is pandas?
• Second, use steps
  • 1. Import the library
  • 2. Read in the data
• to sum up

 

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Preface

Use Scala's syntax to shuffle the array

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1. What is a scrambled array?

Shuffle an array with no duplicate elements. 
Example: 
// Initialize the array with the number set 1, 2 and 3. 
int[] nums = {1,2,3}; 
Solution solution = new Solution(nums); 
// Shuffle the array [1,2,3] and return the result. Any permutation of [1,2,3] should return the same probability. 
solution.shuffle(); 
// Reset the array to its initial state [1,2,3]. 
solution.reset(); 
// Randomly return the result of the array [1,2,3] scrambled. 
solution.shuffle();

2. Concrete realization

code show as below:

class Solution(_nums: Array[Int]) { 

  val nums = _nums 

  /** Resets the array to its original configuration and return it. */ 
  def reset(): Array[Int] = { 

    this.nums 
  } 

  /** Returns a random shuffling of the array. */ 
  //The idea of ​​the shuffling algorithm is to randomly select an element from the subscript range of [0, len] each time and exchange it with the element at the current index subscript position. 
  def shuffle(): Array[Int] = { 
    val len = nums.length 
    var arr = nums.toBuffer//Create a new array 
    for (index <- 0 until len) { 
      var RandomIndex: Int = Random.nextInt(len ) 
      val tmp = arr(index) 
      arr(index) = arr(RandomIndex) 
      arr(RandomIndex) = tmp 
    } 
    arr.toArray 
  } 

}