title: Divisibility By 7
signature: func divisibilityBy7(num int) bool {
test_code: package main
  
  import (
      "fmt"
      "reflect"
      "math"
      "sort"
  )
  
  // SOLUTION CODE
  // ===================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE
  // ===================================
  func validateSolution(actual bool, expected bool) bool {
      return reflect.DeepEqual(actual,expected)
  }
  
  func driver(num int, expected bool) string {
      if validateSolution(PLACEHOLDER_FN_NAME(num),expected) {
              return "PASSED"
      }
      return "FAILED"
  
  }
  
  func main() {
  
      // Use imports to avoid undefined errors
      var _ = reflect.DeepEqual
      _ = math.Abs
      _ = sort.Sort
      result := ""
      result = driver(0, true)
      fmt.Printf("TEST-0...%s\n", result)
      
      result = driver(-21, false)
      fmt.Printf("TEST-1...%s\n", result)
      
      result = driver(7, true)
      fmt.Printf("TEST-2...%s\n", result)
      
      result = driver(63, false)
      fmt.Printf("TEST-3...%s\n", result)
      
      result = driver(84, false)
      fmt.Printf("TEST-4...%s\n", result)
      
      result = driver(73, false)
      fmt.Printf("TEST-5...%s\n", result)
      
      result = driver(81, false)
      fmt.Printf("TEST-6...%s\n", result)
      
      result = driver(-10, false)
      fmt.Printf("TEST-7...%s\n", result)
      
      result = driver(47, false)
      fmt.Printf("TEST-8...%s\n", result)
      
      result = driver(23, false)
      fmt.Printf("TEST-9...%s\n", result)
      
          
  }
source_py: def divisibility_by_7(num):
      if (num < 0):
          return divisibility_by_7((- num))
      if ((num == 0) or (num == 7)):
          return True
      if (num < 10):
          return False
      return divisibility_by_7(((num / 10) - (2 * (num - ((num / 10) * 10)))))
source_cpp: int divisibility_by_7(int num) {
    if ( num < 0 ) return divisibility_by_7 ( - num );
    if ( num == 0 || num == 7 ) return 1;
    if ( num < 10 ) return 0;
    return divisibility_by_7 ( num / 10 - 2 * ( num - num / 10 * 10 ) );
  }