An undirected graph:
0 <--> 1 4
1 <--> 0 4
2 <--> 5
3 <-->
4 <--> 1 0
5 <--> 2

representative[0] = 1
representative[1] = 1
representative[2] = 5
representative[3] = 3
representative[4] = 1
representative[5] = 5

component 0 contains: 1 4 0
component 1 contains: 3
component 2 contains: 5 2
