title: Efficient Way To Multiply With 7
signature: func efficientWayToMultiplyWith7(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(n int, expected int) string {
      if validateSolution(PLACEHOLDER_FN_NAME(n),expected) {
              return "PASSED"
      }
      return "FAILED"
  
  }
  
  func main() {
  
      // Use imports to avoid undefined errors
      var _ = reflect.DeepEqual
      _ = math.Abs
      _ = sort.Sort
      result := ""
      result = driver(41, 287)
      fmt.Printf("TEST-0...%s\n", result)
      
      result = driver(42, 294)
      fmt.Printf("TEST-1...%s\n", result)
      
      result = driver(62, 434)
      fmt.Printf("TEST-2...%s\n", result)
      
      result = driver(4, 28)
      fmt.Printf("TEST-3...%s\n", result)
      
      result = driver(31, 217)
      fmt.Printf("TEST-4...%s\n", result)
      
      result = driver(75, 525)
      fmt.Printf("TEST-5...%s\n", result)
      
      result = driver(5, 35)
      fmt.Printf("TEST-6...%s\n", result)
      
      result = driver(75, 525)
      fmt.Printf("TEST-7...%s\n", result)
      
      result = driver(85, 595)
      fmt.Printf("TEST-8...%s\n", result)
      
      result = driver(19, 133)
      fmt.Printf("TEST-9...%s\n", result)
      
          
  }
source_py: def efficient_way_to_multiply_with_7(n):
      return ((n << 3) - n)
source_cpp: long efficient_way_to_multiply_with_7(long n) {
    return ( ( n << 3 ) - n );
  }