// source http://jsbin.com/ceqeso

<!DOCTYPE html>
<html>
<head>
<meta name="description" content="[add your bin description]" />
  <meta charset="utf-8">
  <title>JS Bin</title>
</head>
<body>

_privateData[this._id] = {
 			  count: numberOfElements,
       		  id: [],
 	 		  sz: []
 		    };

for (i = 0; i < numberOfElements; i++) {
				_privateData[this._id].id[i] = i;
				_privateData[this._id].sz[i] = 1;
 		    }
 	    }

WeightedUFPathCompression.prototype.count = function () {
	 		return _privateData[this._id].count;
 	    };

WeightedUFPathCompression.prototype.find = function (p) {
			var root = p, 
 		        newP; 		
			while (root != _privateData[this._id].id[root]) {
				root = _privateData[this._id].id[root];
			}
			while (p != root) {
 			  newP = _privateData[this._id].id[p];
 			  _privateData[this._id].id[p] = root;
 			  p = newP;
 		    }
            return root;
		};

WeightedUFPathCompression.prototype.isConnected = function (p, q) {
		  return this.find(p) == this.find(q);
        };

WeightedUFPathCompression.prototype.union = function (p,q) {
        var rootp = this.find(p);
        var rootq = this.find(q);
        if (_privateData[this._id].sz[rootp] > _privateData[this._id].sz[rootq]) { 
          _privateData[this._id].id[rootq] = rootp;
          _privateData[this._id].sz[rootp] += _privateData[this._id].sz[rootq];
        } else {
          _privateData[this._id].id[rootp] = rootq;
          _privateData[this._id].sz[rootq] += _privateData[this._id].sz[rootp];
        }
        _privateData[this._id].count -= 1;
      };
      
      return WeightedUFPathCompression;
})();

var obj1 = new WeightedUFPathCompression(10);
console.log(obj1.count() + " components");

obj1.union(1,2);
obj1.union(7,2);
console.log(obj1.isConnected(7,1) + " connected");
console.log(obj1.find(7) + " find");

console.log(obj1.count() + " components");
</script>

_privateData[this._id] = {
 			  count: numberOfElements,
       		  id: [],
 	 		  sz: []
 		    };

for (i = 0; i < numberOfElements; i++) {
				_privateData[this._id].id[i] = i;
				_privateData[this._id].sz[i] = 1;
 		    }
 	    }

WeightedUFPathCompression.prototype.count = function () {
	 		return _privateData[this._id].count;
 	    };

WeightedUFPathCompression.prototype.isConnected = function (p, q) {
		  return this.find(p) == this.find(q);
        };

var obj1 = new WeightedUFPathCompression(10);
console.log(obj1.count() + " components");

obj1.union(1,2);
obj1.union(7,2);
console.log(obj1.isConnected(7,1) + " connected");
console.log(obj1.find(7) + " find");

console.log(obj1.count() + " components");

</script></body>
</html>