sort

asort.java

		public void visit(FlowBlock cur, Frame frame, Collection<FlowBlock> consider) {
			int index = frame.indexOf(cur);
			int dfs = frame.dfsnum;
			frame.low[index] = dfs;
			frame.index[index] = dfs;
			frame.dfsnum++;
			
			frame.stack.push(cur);
			
			for(FlowBlock s : cur.successors()) {
				if(consider.contains(s)) {
					int sIndex = frame.indexOf(s);
					if(frame.index[sIndex] == Frame.TODO) {
						visit(s, frame, consider);
						frame.low[index] = Math.min(frame.low[index], frame.low[sIndex]);
					} else if(frame.index[sIndex] == Frame.DONE) {
						/* Do nothing */
					} else {
						frame.low[index] = Math.min(frame.low[index], frame.index[sIndex]);
					}
				}
			}
			
			if(frame.low[index] == frame.index[index]) {
				SSC ssc = new SSC();
				FlowBlock w;
				do {
					w = frame.stack.pop();
					ssc.blocks.add(w);
					int pIndex = frame.indexOf(w);
					frame.index[pIndex] = Frame.DONE;
				} while(w != cur);
				
				if(ssc.blocks.size() == 1) {
					frame.newOrder.add(0, cur);
				} else {
					frame.newOrder.addAll(0, deobfuscate(ssc.blocks.get(0), ssc.blocks));
				}
			}
		}
		
		public List<FlowBlock> deobfuscate(FlowBlock v, Collection<FlowBlock> consider) {			
			Frame frame = new Frame(new ArrayList<FlowBlock>(), blocks, new LinkedList<FlowBlock>(), blocks.size(), 0);
			
			for(FlowBlock b : consider) {
				int index = frame.indexOf(b);
				frame.index[index] = Frame.TODO;
			}
			
			int vIndex = frame.indexOf(v);
			frame.index[vIndex] = Frame.DONE;
			
			for(FlowBlock s : v.successors()) {
				if(consider.contains(s)) {
					int child = frame.indexOf(s);
					if(frame.index[child] == Frame.TODO) {
						visit(s, frame, consider);
					}
				}
			}
			frame.newOrder.add(0, v);
			
			return frame.newOrder;
		}
		

Frame.java

		static class Frame {
			static final int TODO = Integer.MIN_VALUE + 1;
			static final int DONE = Integer.MIN_VALUE + 2;
			final List<FlowBlock> newOrder;
			final List<FlowBlock> blocks;
			final Deque<FlowBlock> stack;
			final int[] index;
			final int[] low;
			int dfsnum;
			
			Frame(List<FlowBlock> newOrder, List<FlowBlock> blocks, Deque<FlowBlock> stack, int size, int dfsnum) {
				this.newOrder = newOrder;
				this.blocks = blocks;
				this.stack = stack;
				this.dfsnum = dfsnum;
				index = new int[size];
				low = new int[size];
			}
			
			int indexOf(FlowBlock b) {
				return blocks.indexOf(b);
			}
		}

SSC.java

		static class SSC {
			public final List<FlowBlock> blocks = new ArrayList<FlowBlock>();

			@Override
			public String toString() {
				StringBuilder sb = new StringBuilder("SSC: { ");
				Iterator<FlowBlock> it = blocks.iterator();
				while (it.hasNext()) {
					FlowBlock b = it.next();
					sb.append(b.id());
					if (it.hasNext()) {
						sb.append(',');
					}
					sb.append(' ');
				}
				sb.append('}');
				return sb.toString();
			}
		}