/**********************  04-3-S.TXT  ********************
 ***********  Prof. Dr. B. Bartning *********************/

- Remarks about solutions -
ATTENTION, please, here are only program fragments,
this file cannot be compiled as a whole!!
- WITHOUT guarantee! -

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01 // Iteration (Einmaleins)

02 #include <iostream.h>
03 #include <iomanip.h> // für setw()

04 int main()
05 {
06   int run, result;
07   const int factor=6;

08   cout << "Multiplication table with number " << factor << "\n\n";

09   for (run=1; run<=10; ++run) {

10     result = run*factor;
11     cout << setw(2) << run
12          << " * "
13          << setw(2) << factor
14          << " = "
15          << setw(2) << result
16          << endl;
17   }

18   return 0;
19 }

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(a)
07new
       const int factor=3;
oder
       const int factor=423;

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(b)
07new  int factor;
       cin >> factor;
Settling factor not by initializing with
     "const int factor=...;", but by keyboard input.

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(c)
09new   for (run=10; run>=1; --run) {

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(d)  Output only each third line (but up to 30), i. e.
09new   for (run=3; run<=30; run=run+3) {

Or with the compound assignment operator (3.27):
09new   for (run=3; run<=30; run+=3) {

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(e)
- see (4.43), note 1-
Instead of 09 until 17:

   run=1;
   while (run<=10) {

     result = run*factor;
     cout << setw(2) << run
          << " * "
          << setw(2) << factor
          << " = "
          << setw(2) << result
          << endl;

     ++run;
   }

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(f)
Instead of 09 until 17:

   run=1;
   do {

     result = run*factor;
     cout << setw(2) << run
          << " * "
          << setw(2) << factor
          << " = "
          << setw(2) << result
          << endl;

     ++run;
   } while (run<=10);

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(g)
#include <iostream.h>
#include <iomanip.h>

int main()
{
  int row, col;

  cout << "Multiplication table\n\n";

  cout << setw(4) << ' '; // oder: cout << "   ";
  for (col=1; col<=10; ++col)
     cout << setw(4) << col;
  cout << endl;

  for (row=1; row<=10; ++row) {
    cout << setw(4) << row;
    for (col=1; col<=10; ++col)
       cout  << setw(4) << row*col;
    cout << endl;
  }

  return 0;
}

Or with column/row delimiters:

#include <iostream.h>
#include <iomanip.h>

int main()
{
  int row, col;

  cout << "Multiplication table\n\n";

  cout << "     | ";
  for (col=1; col<=10; ++col)
     cout << setw(4) << col;
  cout << endl;
  cout << "  ---+-";
  for (col=1; col<=10; ++col)
     cout << "----";
  cout << endl;

  for (row=1; row<=10; ++row) {
    cout << setw(4) << row
         << " | ";
    for (col=1; col<=10; ++col)
       cout  << setw(4) << row*col;
    cout << endl;
  }

  return 0;
}

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