triangle pattern centered

i want to create a pattern in c++ that looks like a trianlge(or half a diamond) using asteriscks: the pattern should have 1, 2, 3, 4, and end in 5 stars like this

  *
  **
 ***
 ****
*****

(but straight!) my code is as follows:

-`#include using namespace std; int main() {

int size;
cout<<"size:"<<endl;
cin>>size;

int blank=size/2;
int newsize=1;
for (int i=0; i<=size/2; i++)
{
    for(int j=blank;j>0;j--)
        cout <<" ";
    blank--;
    for(int j=newsize; j>0; j--)
        cout <<"*";
    newsize+=2;
    cout <<endl;
}


return 0;

} ` my only problem with it is that it开发者_开发技巧 displays 1, 3,and 5 stars like this.

  *
 ***
*****

its just a minor problem but although i have changed different parts of the code i dont seem to get it right.

any suggestions?

thanks :)

I'm not sure what you mean by "but straight", so I'll just ignore that for now...

Start with blank the same value as size, so that you can decrement the value each time without having to decrement by a half:

int blank=size;

Loop up to size instead of size/2 to get more lines:

for (int i=0; i<=size; i++)

Decrement by two in the loop for spaces to get half the number of spaces:

for(int j=blank;j>0;j-=2)

Increase the size by one instead of two to get the slower increase:

newsize++;

That should produce the output that you showed.

Edit:

I tested this to be sure, and the output is:

   *
  **
  ***
 ****
 *****
******

To get the exact output that you asked for, start with blank one less:

int blank=size - 1;

Did I get it right: you want to place some asterisks on borders of character places? If so, it isn't possible. Every asterisk (or any other symbol), when displayed in monospace fonts, will reside in a middle of a character place, like in a grid. You can place asterisks inside the cells, but you cannot place asterisks on the borders of the grid.

int NUMLINES = 5;

void display(int, char);

void main(){
for (int i=1; i<= NUMLINES; ++i){
    display((NUMLINES + 1 - i), ' ');
    display(( 2 * i - 1 ), '*');
    cout << endl;
}

}
void display (int howmany, char symbol){
for (int i = 1; i<=howmany; ++i)
 cout << symbol;
}