2 dimensional array

My current program takes user input for an expression tree, example *2x and outputs

* 0 0
2 0 0
x 0 0

*2x is stored in a string.
the 2nd and 3rd columns represent a left-child right-child array. When one of the following operands are input "+ - * / " the zeros need to be changed to the locations of their child's. Like in this example 2 would be the left child of * and x would be the right child so the output should look like

* 1 2
2 0 0
x 0 0

The only way I have thought to do this is to use a switch statement to look for the operands but I don't know how to call on the index that it's child is in.
This is my code:

Code:

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#include <iostream>
#include <iomanip>

using namespace std;

int main()
{
  char s[50];
  cout << "Input the prefix expression.\n";
  cin >> s;
  cout << "\nThe expression tree is:";

 
  int row = strlen(s);
  int col = 2;
  char a[10][10];
  int i, j, c;
  int pos;

  for (j = 0; j < row; j++)
  {
      a[j][0] = s[j];

  for(i = 1; i <= col; i++)
  {
      a[j][i] = '0';
     
      switch (s[j]) {
        case '+':
        case '-':
        case '*':
        case '/':
       
          a[j][i] =;
          break;
          }
  }
  }

  for (j = 0; j < row; j++)
  {
      cout << "\n";
  for(i = 0; i <= col; i++)
  {
      cout << a[j][i] << setw(2);
  }
  }

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Quote:

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Originally Posted by whitey300

My current program takes user input for an expression tree, example *2x and outputs

* 0 0
2 0 0
x 0 0

*2x is stored in a string.
the 2nd and 3rd columns represent a left-child right-child array. When one of the following operands are input "+ - * / " the zeros need to be changed to the locations of their child's. Like in this example 2 would be the left child of * and x would be the right child so the output should look like

* 1 2
2 0 0
x 0 0

The only way I have thought to do this is to use a switch statement to look for the operands but I don't know how to call on the index that it's child is in.

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You won't know until you get there. You can't be guaranteed that the next two items will be your operands (if it was something like *+3x2, for instance, I'm betting you would want to print out

Code:

---

* 1 4
+ 2 3
3 0 0
x 0 0
2 0 0

---

right?)

So, you'll need to set up something very much like a stack so that, as you read along you can see where the thing you are reading belongs.

yes that is exactly how I want it to output. How do I set up a stack for it to work though?

however I'm not allowed to use classes, pointers, or structs

Quote:

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Originally Posted by whitey300

however I'm not allowed to use classes, pointers, or structs

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Not allowed to, eh? Then you'll have to mock up a stack using an array (keep track of the "top" of the stack with an index counter).