A quick union find data structure for javascript
var UnionFind = require('unionfind')
var uf = new UnionFind(size[, key])
Initialize the Union Find data structure with number of distinct groups to begin with. Each group will be referred to as index of the array of size size starting at 0. You can also provide an optional key function that maps these indices in a certain way. For example if you would like to refer to the groups starting with 1 provide the function function(a){return a-1;}. The default value is function(a){return a;}.
uf.union(p, q);
Combine elements in groups p and q into a single group. In other words connect the two groups.
uf.find(p);
Return the root (value) of the group in which p is.
uf.connected(p, q);
Returns true if p and p are both in same group, false otherwise.
uf.size();
Returns the number of elements of uf object.
uf.count();
Returns the number of distinct groups left inside the object.