Write out a triangle

[Willyboy]

Hello!
I hope there isn't a thread about this already, if there is I blame my real bad skills on searching.. :P

Anyhow, I need to train my knowledge in c++ and decided to make a program that makes a triangle (90 degrees bottom left corner.. Dont know the english word for it.. equilateral?) from what the user types.

designate sign: +
designate height: 5

+
++
+++
++++
+++++

Thats what I wanna do..
My code right now is:

char sign;
    int height;
    cout << "Designate sign: ";
    cin >> sign;
    cout << "Designate height: ";
    cin >> height;
    for (height < 50; height--;) {
        cout << height * sign << endl;
         }

I know it's not done, but I have no clue at all of how I should continue...
Thanks for help! =)

[Bazzy]

Your loop should look something like this: for ( int i = 0; i < height; i++ )
Then you should have another loop inside that or use setw / setfill http://www.cplusplus.com/reference/iostream/manipulators/setfill/

[Willyboy]

Thanks!

Though, I don't understand how I shall use setw / setfill, and I don't get it from the link you sent either..
Pretend that I'm a child, and explain to me ;) Haha

[TheNo1]

#include <iostream>
using namespace std;
int main (){
int i,j,k,a;
char mat[5][5];
for (i=0;i<5;i++){
for(j=0;j<5;j++){
k=(i-j);
do{
if (k>=0){
mat[i][j]='+';
cout<<mat[i][j];}
else {
cout<<" ";}}
while (a=0);}
cout<<"\n";}
system("PAUSE");
return 0;}
---------------------------------------------------------
copy this and run it...
---------------------------------------------------------

[Willyboy]

Yeah, that is working alright. But my goal was to let the user designate wich kind of sign (for example: + * / A B 1.. etc. etc.), and then the height of the triangle.

So that it could look like:

1
11
111

*
**

/
///
////
/////

And so on...

If someone could explain to me how to do this, or give me a code to it so that I could analyze it and learn, I'd be overjoyed :)

Thanks for the time you put in though TheNo1, much appriciated! :)

[TheNo1]

Np! :)

working on what you asking 4 ..

[TheNo1]

Done :D
--------------------------
#include <iostream>
using namespace std;
int main (){
int i,j,k,a,R,C,c;
char mat[99][99];
cout<<"Enter ROWS"<<endl;
cin>>R;
cout<<"Enter COLS"<<endl;
cin>>C;
cout<<"Enter char"<<endl;
cin>>c;
for(i=0;i<R;i++){
for(j=0;j<C;j++){
k=(i-j);
do{
if(k>=0){
mat[i][j]=c;
cout<<mat[i][j];}
else{
cout<<" ";}}
while(a=0);}
cout<<"\n";}
system("PAUSE");
return 0;}
--------------------------------------------------------------
// (c) TheNo1 ; [e-mail] :)
-----------------------------------------------------

[helios]

What the...? Don't do other people's homework!

EDIT: And your style is god-awful.

[TheNo1]

Thanks for your appreciation.
I'll try hard to improve my "STYLE"..
So that you like it.

[mcleano]

Helios its christmas be nice! :)

#include <iostream>
#include <string>

int main()
{
    char sign;
    int row = 0;
    
    std::cout << "Designate sign: ";
    std::cin >> sign;
    std::cin.ignore();
    
    std::cout << "Designate No. of rows: ";
    std::cin >> row;
    std::cin.ignore();
    
    for(int i=1; i<=row; i++) {
      std::string str(i, sign);
      std::cout << str << "\n";
    }
        
    std::cin.get();
    return 0;
}

Look at the constructor for a string object: http://www.cplusplus.com/reference/string/string/string/

[TheNo1]

Wow :) Mcleano, I really like it.
It's more simple and effective.
But I think you should add the way we see the triangle (for example the +).
Right now it's showing the triangular shape, by the last number that the user enters.
It's not such a big problem .. The program would be perfect in this manner.
Merry Christmas.... :D

[mcleano]

I don't understand what it's missing? The user can specify both the sign( a '+' for example) and the number of rows.

[TheNo1]

sry.. My mistake.

[Willyboy]

@Helios
Homework? :P
Nah, I'm trying to learn C++, not make homework..

@Mcleano
HUGE thanks for the code, now I can analyze and (hopefully xD) learn something new :)
Thanks again! :)

[BettyBoopTS]

here is a simple code to accomplish the character triangle.

#include <iostream>
using namespace std;



int main()

{
     char a;
     int b,c,d;




     cout << "designate sign";

     cin >> a;

     cout << "designate height";

     cin >> b;





     for (c=1;c<=b;c++)
     
          {
               {

                    for(d=1;d<=c;d++) cout << a;
               }


               cout << "\n";
          }

     return 0;
}

input a'+', b'10'.
output:

+
++
+++
++++
+++++
++++++
+++++++
++++++++
+++++++++
++++++++++

[Willyboy]

Thanks BettyBoopTS!
That code is a bit easier, I am more on that level than on mcleanos, even though that was good too.

Though I have a question:

To what good is the 37:th line?
(cout << "\n"; )

I mean.. All it does is to cout a new line? And if that line is removed it's not working anymore..
Why is it not possible to only use a << endl; in the "for-section" ?

Looks bad with a cout-line like that, but is it the only solution in this code?

[Bazzy]

That prints the newline after the inner loop has drawn the row of characters

[helios]

Why is it not possible to only use a << endl; in the "for-section" ?

Who said it's not?

[BettyBoopTS]

I'm just a beginner myself, and honestly, I may sound like an idiot, but I havnt come across the 'endl' command in the c++ beginners manual i am studying, yet. but,, why does that look bad? i dont understand.

[Willyboy]

@Helios.
True, none. Though I tried to use it and then nothing worked, and yes I did use it at different locations. (can't remember where though)
Therefore I, probably I was wrong, guessed that it's not possible.

@Betty
Bad is probably wrong choice of words, but in my opinion it looks... My english wordbank is too small right now, so bad is the only word I can figure out..
To only cout out a "\n" looks in my opinon not good, if someone would look at the code. To use a << endl; is "nicer".


Anyhow..
The cout-line is a part of... Let's see.. The loop on line 28, am I right?

That would explain why my <<endl; didn't work since I tried to insert it in the second loop.... :rolleyes: