Programming Assignment 3
The World Chess Federation (F.I.D.E) are planning the World Chess Championship. tournament. One of the constraints they need to respect is to pair
chess players from different countries. There are N professional chess players
numbered from 0 to N − 1 . FIDE does not have information about the citizenship of each chess player but they do know have some information about which
players belong to the same country. Your task is to compute the number of
ways possible to play a match between 2 players from different countries. You
are provided with enough number of pairs so you succeed in your mission even
though you don’t know their citizenship right away. For example, if the players
1 , 2 and 3 are from the same country then the 2 pairs (1, 2) and (2, 3) give
sufficient information and the third pair (1, 3) is not needed.
1 Input and Output
The first line contains two integers, N and I separated by a single space. I lines
follow. Each line contains 2 integers A and B separated by a single space such
0 ≤ A, B ≤ N − 1
1 ≤ N ≤ 105
1 ≤ I ≤ 104
A and B are chess players from the same country. The input should be taken
from a separate input file. The output should be a single line displaying the
number of permissible ways to choose a pair of chess players. There is no need
to write it in a separate output file. You can display it on the console.
2 Sample Input
3 Sample Output
We have the following pairs (0, 2),(0, 3),(1, 2),(1, 3),(0, 4),(1, 4),(2, 4),(3, 4) where
players are from different countries in each pair.