Help With Pascal's Triangle in C++

[lostinthespiral]

I am new to programming and am having REAL trouble trying to output Pascal's Triangle (formatted into a triagle) using multidimensional arrays. I would really appreciate some help.

In the program, the user is supposed to input the # of rows desired (up to 15... or else it won't fit on the screen). I would REALLY appreciate it if someone could help me. Thank you!

The output needs to look like this (but formatted to look like a triangle):

1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
1 6 15 20 15 6 1
1 7 21 35 35 21 7 1
1 8 28 56 70 56 28 8 1
1 9 36 84 126 126 84 36 9 1
1 10 45 120 210 252 210 120 45 10 1
1 11 55 165 330 462 462 330 165 55 11 1
1 12 66 220 495 792 924 792 495 220 66 12 1
1 13 78 286 715 1287 1716 1716 1287 715 286 78 13 1

[lostinthespiral]

Here are some of the things the teacher gave us to work on... I've looked at some example code, but nothing I've tried seems remotely close. Here are some links he gave the class:
http://met.dnsalias.net:1111/teaching/f04/program5.jsp
http://en.wikipedia.org/wiki/Pascal%27s_triangle

[daniusr]

The following link may be helpful: http://www.codechamber.com/tutorials/beginningcpp/pascal.cpp

[Narue]

>The following link may be helpful
I doubt it, unless the OP is still having trouble with this assignment three years later. :icon_rolleyes:

[parth89]

what ur looking for is this.

#include<iostream.h>
#include<conio.h>
void display(int[],int);
int pas(int n)
{
  int f=0;
  while(n>0)
  {
    f=f+n;
    n--;
  }
  return(f-1);
}
void main()
{
  clrscr();
  int n,a[100];int z=0;
  cout<<"enter n";cin>>n;
  for(int i=0;i<4;i++)
  {
    a[i]=1;
  }
  for(int x=3;x<n;x++)
  {
    z=pas(x);a[z]=1;z++;a[z]=1;
  }
  int c=0; c=pas(n); a[c]=1;
  for(int b=3;b<=n;b++)
  {
    int d=0; int e=0,f=0;
    e=pas(b-1)+2;
    f=pas(b-1);
    d=pas(b);
    while(e!=d)
    {
      a[e]=a[f]+a[f-1];
      e++;f--;
    }
  }
  display(a,n);
  getch();
}

void display(int a[],int n)
{
  int j=40,k=10;int s=0;int p=1;
  gotoxy(j,k);
  cout<<a[s];
  for(int t=1;t<n;t++)
  {
    p++; int h=0;j=j-2; k=k+2;
    for(int w=1;w<=p;w++)
    {
      s++;
      gotoxy(j+h,k);
      cout<<a[s];
      h=h+4;
    }
  }
}

[parth89]

here is the code

[Narue]

It's still a three year old thread. Though it is mildly humorous that people will bump ancient threads with bad advice and/or bad code. However, since this thread is so old, and because I'm bored, I'll reject your code and substitute my own:

#include <iostream>

int factorial ( int n, int k )
{
  int result = 1;

  while ( k-- > 0 )
    result *= n--;

  return result;
}

int pascal_triangle ( int n, int k )
{
  return factorial ( n, k ) / factorial ( k, k );
}

int main()
{
  for ( int i = 0; i < 9; i++ ) {
    for ( int j = 0; j <= i; j++ )
      std::cout<< pascal_triangle ( i, j ) <<' ';
    std::cout<<'\n';
  }
}

[invisal]

How about my solution. Faster and can handle more rows. However,
this code is written in C. I will translate it to C++, if you want.

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int n, i, j;
    printf("How many rows you want to show?: ");
    scanf("%d", &n);
    for (i=0; i<n; i++) {
        int c = 1;
        for(j=i; j>=0; j--) {
            printf(" %d", c);
            c = c * j/(i-j+1);
        }
        printf("\n");
    }
}

[amrita76]

I am new to programming and am having REAL trouble trying to output Pascal's Triangle (formatted into a triagle) using multidimensional arrays. I would really appreciate some help.

In the program, the user is supposed to input the # of rows desired (up to 15... or else it won't fit on the screen). I would REALLY appreciate it if someone could help me. Thank you!

The output needs to look like this (but formatted to look like a triangle):

                                         1
                                     1     1
                                  1     2     1
                               1     3     3     1
                            1     4     6     4     1
                         1     5     10    10    5     1
                      1     6     15    20    15    6     1
                   1     7     21    35    35    21    7     1
                1     8     28    56    70    56    28    8     1
             1     9     36    84    126   126   84    36    9     1
          1     10    45    120   210   252   210   120   45    10    1
       1     11    55    165   330   462   462   330   165   55    11    1
    1     12    66    220   495   792   924   792   495   220   66    12    1
 1     13    78    286   715   1287  1716  1716  1287  715   286   78    13    1

end quote.

for (i=1;i<=6;i++)
{
for(j=6;j>=i;j--)
{
printf("*");
}
printf(\n);
}

[nikita_3553]

#include <iostream>
using namespace std;

int main()
{
    const int ROWS = 15, COLS = 15;
    int pascal[ROWS][COLS] = {};

    pascal[0][0] = 1;
    cout << pascal[0][0] << endl;
    for ( int r = 1; r < ROWS; r++ )
    {
        pascal[r][0] = 1; // when c = 0, set the values to 1
        pascal[r][r] = 1; // when c = r (end of triangle), set the values to 1
        cout << pascal[r][0] << "    ";
        for ( int c = 1; c < r; c++ )
        {
            pascal[r][c] = pascal[r-1][c-1] + pascal[r-1][c];
            cout << pascal[r][c] << "    ";
        }
        cout << pascal[r][r] << endl;
    }
}

[deceptikon]

Thanks for the input nikita, but was it really worth bumping a 7 year old thread that already had working example code?