Multiply alternative Stellen in einem Array mit C#

Question

Im ein Schulprojekt zu tun in dem ich habe einen GTIN Code zu finden, wenn die ersten sieben Ziffern angegeben, hier ist der Code:

Console.WriteLine("Please enter the first 7 digits of the code");// asking the user to input the digits of the code 
      int[] GTIN = new int[7];//creating the integer array GTIN to hold the first 7 digits 
      GTIN[0] = Convert.ToInt32(Console.ReadLine()) * 3;//takes the first digit of the code and multiplies it by 3 
      GTIN[1] = Convert.ToInt32(Console.ReadLine()) * 1;//takes the second digit of the code and multiplies it by 1 
      GTIN[2] = Convert.ToInt32(Console.ReadLine()) * 3;//takes the third digit of the code and multiplies it by 3 
      GTIN[3] = Convert.ToInt32(Console.ReadLine()) * 1;//takes the fourth digit of the code and multiplies it by 1 
      GTIN[4] = Convert.ToInt32(Console.ReadLine()) * 3;//takes the fith digit of the code and multiplies it by 3 
      GTIN[5] = Convert.ToInt32(Console.ReadLine()) * 1;//takes the sixth digit of the code and multiplies it by 1 
      GTIN[6] = Convert.ToInt32(Console.ReadLine()) * 3;//takes the seventh digit of the code and multiplies it by 3 

      int sum = GTIN.Sum();// adds up the product of the multiplications and stores them in int sum 
      Console.WriteLine("The total is " + sum);//prints the total to the console 
      int roundup = ((sum - sum % 10) + 10);// takes the sum and rounds it up to the nearest 10 and stores it in int roundup 
      Console.WriteLine(roundup);// prints roundup 
      int finaldigit = roundup - sum;// woks out the final digit of the code 
      Console.WriteLine("The eighth digit of your code is " + finaldigit);// prints the final digit 

      Console.WriteLine("Enter the code you want to verify");//asks the user to input the 8 digit code that they want to verify 
      int[] GTIN2 = new int[8];//creating the integer array GTIN2 to hold the first 8 digits 
      GTIN2[0] = Convert.ToInt32(Console.ReadLine()) * 3;//takes the first digit of the code and multiplies it by 3 
      GTIN2[1] = Convert.ToInt32(Console.ReadLine()) * 1;//takes the second digit of the code and multiplies it by 1 
      GTIN2[2] = Convert.ToInt32(Console.ReadLine()) * 3;//takes the third digit of the code and multiplies it by 3 
      GTIN2[3] = Convert.ToInt32(Console.ReadLine()) * 1;//takes the fourth digit of the code and multiplies it by 1 
      GTIN2[4] = Convert.ToInt32(Console.ReadLine()) * 3;//takes the fith digit of the code and multiplies it by 3 
      GTIN2[5] = Convert.ToInt32(Console.ReadLine()) * 1;//takes the sixth digit of the code and multiplies it by 1 
      GTIN2[6] = Convert.ToInt32(Console.ReadLine()) * 3;//takes the seventh digit of the code and multiplies it by 3 
      GTIN2[7] = Convert.ToInt32(Console.ReadLine()) * 1;//takes the eighth digit of the code and multiplies it by 1 

      int sum2 = GTIN2.Sum();// adds up the product of the multiplications and stores them in int sum2 
      Console.WriteLine("The total is " + sum2);// prints the total of the sum 

      if (sum2 % 5 == 0)// opens if statement; if the remainder of sum2 divided by 5 ends in a 0 then... 
      { 
       Console.WriteLine("Your code has been verified");//print your code has been verifed 
      } 
      else// else 
      { 
       Console.WriteLine("The code is incorrect");// print code is incorrect 
      } 

      Console.ReadLine();//end 

Wie können Sie diese sehen funktioniert, aber es ist nicht effizient, ich muss herausfinden, wie man die Multiplikation als Schleife macht, aber ich weiß nicht wie. Danke im Voraus.

Answer 1

so etwas wie dies versuchen,

int sum = 0,value=0; 
for(int i=0;i<GTIN.Length;i++) //allows you to fill the array 
{ 
    Console.WriteLine("Please enter an integer"); 
    if((i%2)==0) 
     value = 3; 
    else 
     value = 1; 
    sum += value * int.Parse(Console.ReadLine()); 
} 

Answer 2

sum *= num[i]; werden Ihre Aufgabe erledigen.

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