Can you explain this code?

`

program exercise1;
uses crt;
var
    x,y,z,i,j,k,temp : integer;
begin
    clrscr;
    write('input x: ');readln(x);
    write('input y: ');readln(y);
    write('input z: ');readln(z);

    for i:= 1 to x do
        for j:= 2 to y do
            for k:= 1 to z do
                temp:= temp+(i*j*k);
    writeln(temp);
    readln;
end.

`

my understanding is like this:

1. if we input x,y, then z with value 2,2,2, then the output will be 18
2. in for variable k first looping is (1 x 1 x 1) = 1 and for second looping is (1 x 1 x 2) = 2
3. in for variable j (1 x 2 x 2) = 4
4. in for variable i ( 1 x 1 x 1) = 1 and for second looping is ( 2 x 2 x 2) = 8

if we sum 2 + 4 + 8 = 14, please help with the correction

>Solution :

First of all, temp is not initialized, so it can contain rubbish. You will need to fix it, by initializing temp with a value. In this answer I will assume that you have already fixed that bug and temp is initialized with 0.

x, y and z are user-defined values.

• i is looping from 1 to x
• j is looping from 2 to y
• k is looping from 1 to z

Each time their product is added to temp.

x=2, y=2, z=2

• i is 1
  • j is 2
    • k is 1
      • we add 1 * 2 * 1 = 2 to temp, resulting in 2
    • k is 2
      • we add 1 * 2 * 2 = 4 to temp, resulting in 2 + 4 = 6
• i is 2
  • j is 2
    • k is 1
      • we add 2 * 2 * 1 = 4 to temp, resulting in 6 + 4 = 10
    • k is 2
      • we add 2 * 2 * 2 = 8 to temp, resulting in 10 + 8 = 18

The mistake in your calculation

You have missed the case of (2 x 2 x 1), this is why you reached 14 instead of 18. In order to analyze problems such as this one, it is recommendable to either take a pen & paper and go through it step-by-step, or debug your code using a debugger.