title: Number Visible Boxes Putting One Inside Another
signature: func numberVisibleBoxesPuttingOneInsideAnother(arr []int, n int) int {
test_code: package main
  
  import (
      "fmt"
      "reflect"
      "math"
      "sort"
  )
  
  // SOLUTION CODE
  // ===================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE
  // ===================================
  func validateSolution(actual int, expected int) bool {
      return reflect.DeepEqual(actual,expected)
  }
  
  func driver(arr []int, n int, expected int) string {
      if validateSolution(PLACEHOLDER_FN_NAME(arr, n),expected) {
              return "PASSED"
      }
      return "FAILED"
  
  }
  
  func main() {
  
      // Use imports to avoid undefined errors
      var _ = reflect.DeepEqual
      _ = math.Abs
      _ = sort.Sort
      result := ""
      result = driver([]int{2, 3, 17, 17, 18, 28, 28, 29, 34, 43, 44, 52, 54, 80, 84, 84, 91, 92, 97}, 
  	12, 7)
      fmt.Printf("TEST-0...%s\n", result)
      
      result = driver([]int{-94, -90, -90, -78, -34, -26, -10, 4, 24, 28, 64, 70, 72, 74, 80, 82}, 
  	10, 2)
      fmt.Printf("TEST-1...%s\n", result)
      
      result = driver([]int{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 
  	40, 15)
      fmt.Printf("TEST-2...%s\n", result)
      
      result = driver([]int{2, 3, 5, 8, 12, 16, 20, 30, 37, 53, 55, 62, 76, 81, 83, 87, 88, 96}, 
  	9, 3)
      fmt.Printf("TEST-3...%s\n", result)
      
      result = driver([]int{-94, -92, -60, -58, -54, -42, -36, -12, -8, -2, 8, 14, 18, 20, 26, 32, 38, 56, 58, 60, 70, 78, 80, 86, 98}, 
  	18, 4)
      fmt.Printf("TEST-4...%s\n", result)
      
      result = driver([]int{0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 
  	9, 4)
      fmt.Printf("TEST-5...%s\n", result)
      
      result = driver([]int{1, 1, 2, 3, 3, 11, 16, 18, 19, 21, 21, 22, 22, 24, 27, 28, 29, 43, 43, 52, 55, 57, 60, 62, 62, 63, 65, 66, 70, 70, 73, 77, 78, 79, 79, 80, 85, 85, 86, 88, 89, 90, 97, 98}, 
  	30, 13)
      fmt.Printf("TEST-6...%s\n", result)
      
      result = driver([]int{-94, -82, -80, -78, -68, -60, -58, -44, -44, -42, -30, -30, -22, -18, -18, -14, -14, -10, -8, -6, 4, 4, 6, 12, 12, 14, 18, 30, 44, 48, 50, 52, 54, 80, 86, 88, 88}, 
  	21, 1)
      fmt.Printf("TEST-7...%s\n", result)
      
      result = driver([]int{0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 
  	7, 3)
      fmt.Printf("TEST-8...%s\n", result)
      
      result = driver([]int{3, 5, 5, 10, 12, 16, 22, 31, 31, 32, 39, 43, 43, 47, 49, 50, 51, 52, 52, 56, 59, 59, 62, 69, 69, 71, 75, 81, 82, 83, 83, 86, 89, 90, 90, 96}, 
  	28, 17)
      fmt.Printf("TEST-9...%s\n", result)
      
          
  }
source_py: def number_visible_boxes_putting_one_inside_another(arr, n):
      q = collections.deque([])
      arr.sort()
      q.append(arr[0])
      for i in range(1, n):
          now = q[0]
          if (arr[i] >= (2 * now)):
              q.popleft()
          q.append(arr[i])
      return len(q)
source_cpp: int number_visible_boxes_putting_one_inside_another(vector<int> arr, int n) {
    queue < int > q;
    sort(arr.begin(), arr.end());
    q . push ( arr [ 0 ] );
    for ( int i = 1;
    i < n;
    i ++ ) {
      int now = q . front ( );
      if ( arr [ i ] >= 2 * now ) q . pop ( );
      q . push ( arr [ i ] );
    }
    return q . size ( );
  }