Question

Program lalala; var n,p:integer; begin write('Введите четырёхзначное значное число'); p:=(n div 1000)*(n mod 10); n:=(n mod 1000 div 10); p:=p*(n div 10)*(n mod 10); writeln('произведение равно',p); end. Скажите, что здесь не так

Answer 1

write('Введите четырёхзначное значное число'); после этого должно быть

read(n);

Answer 2

In the provided code, there are a few issues that need to be addressed:

1. Variable initialization: The variables n and p are used in the program, but they are not initialized before being used. It's important to initialize variables before performing any operations on them.

2. User input: The code is supposed to take user input for the variable n, but the input statement is missing. You need to add a line to read the user's input and store it in the variable n.

3. Reading integer input: When reading integer input, you should use ReadLn instead of WriteLn to get the user's input.

4. Division by zero: There's a potential issue with division by zero in the second line of the code, as the value of n is not yet initialized when the expression (n mod 1000 div 10) is evaluated.

5. Code organization: The code could be better organized with appropriate comments and spacing to make it more readable.

Here's a corrected version of the code with the above issues addressed:

pascalCopy code
Program lalala;
var
  n, p: integer;

begin
  // Read user input for n
  Write('Введите четырёхзначное значение числа: ');
  ReadLn(n);

  // Perform calculations
  p := (n div 1000) * (n mod 10);
  n := (n mod 1000) div 10;
  p := p * (n div 10) * (n mod 10);

  // Display the result
  WriteLn('Произведение равно: ', p);
end.

Now the code should work correctly and prompt the user to input a four-digit number, calculate the product of its first and last digits, and then display the result.