gistfile1.js

DisjointSet = function(size) {
        var instance = this,
            parent_,
            i;

        size = instance.size = size || 0;

        parent_ = instance.parent = new Uint32Array(size);

        for (i = 0; i < size; i++) {
            parent_[i] = i;
        }
    };

    DisjointSet.prototype = {
        parent: null,

        size: null,

        find: function(i) {
            var instance = this,
                parent_ = instance.parent,
                result;

            if (parent_[i] === i) {
                return i;
            }
            else {
                result = instance.find(parent_[i]);

                parent_[i] = result;

                return result;
            }
        },

        union: function(i, j) {
            var instance = this,
                iRepresentative = instance.find(i),
                jRepresentative = instance.find(j);

            instance.parent[iRepresentative] = jRepresentative;
        }
    };