Creating a triangle in C++

[isabellegagnier]

I need to create a triangle in C++ that will take the user inputted letter (capital) and then create a triangle that will look like. I can only use nested loops NO arrays or strings

Enter a letter: F
F
FE
FED
FEDC
FEDCB
FEDCBA

here is the code i have so far i am creating a triangle but not exactly the one i require

#include <iostream>
using namespace std;
int main () 
{
	char letter, last;
	char row, col;
	
	cout << "Entre a letter: ";
	cin >> letter;
	letter = toupper(letter);
		
	for (row = 0; row < letter; row++)
		{
			for (col = 0; col <= row; col++)
				cout << letter ;
				last = letter;
				 cout << last << letter<< letter--;
				 cout << endl;
		}
    return 0;
}

[Clinton Portis]

can only use nested loops NO arrays or strings

I was kinda stumped at first until I came up with a linked-list of chars:

#include<iostream>
#include<cctype>
using namespace std;

struct node
{
     char letter;
     node *next;
};

int main()
{
     node *head_ptr = new node;
     node *list = head_ptr;
     int counter = 0;
     char input, ans;

     do{

               cout << "\nEnter a letter:  ";
               cin >> input;

               list->letter = toupper(input);      
               list->next = new list;
               list = list->next;

               counter++;

               cout << "\nWould ye' like to enter another letter? (Y/N) ";
               cin >> ans;                     

          }while(toupper(ans) == 'Y');

          list->next = NULL;
          list = head_ptr;

          int j=1;
          while(list)
          { 
               for(int i=0;  i<j && list; i++)
               {
                    cout << list->letter; 
                    list = list->next;
               }

               cout << endl;
               j++;
          }

         list = head_ptr;
         node temp;

          while(list)
          {
               temp = list;
               list = list->next;
               delete temp;               
          }         

return 0;
}

This code creates a 'linked-list' of nodes that contain space for 1 char per node. After the user is prompted to enter several letters, the list is traversed (starting from the head pointer) and displayed to the screen in a tree type manner.

This is untested code, so it might contain simple/easy to fix errors.

[Clinton Portis]

line #24 should be: list->next = new node;

[isabellegagnier]

Thanks fro your help
my only problem is that i am so new at this and have yet to learn about linked lists of char. there as to be a stupid way for newbies like me, i do have a class tomorrow and can ask the teacher, and i will keep on trying. if you try my code it also does not stop at letter it keeps going on through the ASCII chart

Again thanks

[Clinton Portis]

The requirements for this assignement approach an intermediate level of programming since we cannot use arrays or <string> class objects. Being that we are unable to use arrays, we cannot use 'c-strings' (char arrays). So what's left?

Our options include: STL containers and linked lists or just create a ton of singular char variables and hope we have enough for user input. Another option would be to write all the char variables to a file.

I'm open to suggestions, I think the method I used was probably the most primitive of options that I could think of.

[isabellegagnier]

i have managed to solve my own problem!!
let me share this

{
	char letter, maxrow;
	char row, col;
	
	cout << "Enter a letter: ";
	cin >> letter;
	letter = toupper(letter);
	maxrow = letter;
	
	for (row = 'A'; row <= maxrow; row++)
		
	{
		for (col = 'A'; col <= row; col++, letter--)
			cout << letter;
		cout<< endl;
		letter=maxrow;	
		
	}
    return 0;
}