[R] Help to make a specific matrix

[Jose Claudio Faria]

Dear R users,

The solution is probably simple but I need someone to point me to it.
How can I to generate a matrix from a numeric sequence of 1:10 like 'A' or 'B' 
below:

A)
|--------------------|
|      1  2  3  4  5 |
|--------------------|
| 1 |  0             |
| 2 |  1  0          |
| 3 |  2  5  0       |
| 4 |  3  6  8  0    |
| 5 |  4  7  9 10  0 |
|--------------------|

B)
|--------------------|
|      1  2  3  4  5 |
|--------------------|
| 1 |  0  1  2  3  4 |
| 2 |  1  0  5  6  7 |
| 3 |  2  5  0  8  9 |
| 4 |  3  6  8  0 10 |
| 5 |  4  7  9 10  0 |
|--------------------|

This question is related with the possible combinations of five objects two the 
two, i.e, C(5,2).

Any help would be greatly appreciated.

Regards,
-- 
Jose Claudio Faria
Brasil/Bahia/UESC/DCET
Estatistica Experimental/Prof. Adjunto
mails:
  joseclaudio.faria at terra.com.br
  jc_faria at uesc.br
  jc_faria at uol.com.br
tel: 73-3634.2779