Try to implement Tarjan iteration version

use stack like topological sort to simulate recursion
use stack to contain components
still failed with some input data:
12
1 2
2 3
2 4
2 5
3 6
4 5
4 7
5 2
5 6
5 7
6 3
6 8
7 8
7 10
8 7
9 7
10 9
10 11
11 12
12 10

graph.search.js

@@ -149,7 +149,7 @@
 
 						while (!component.isEmpty() && 
 							(h=component.peek(), true) &&
-							(/*frontier.isEmpty() ||*/ low[h] === last[0] || low[h] === last[1])) {
+							(frontier.isEmpty() || low[h] === last[0] || low[h] === last[1])) {
 							c.push(component.pop());
 							last[0] = g.__labelAt__(h);
 							last[1] = low[h];