diff --git a/algs4/extract-algs4 b/algs4/extract-algs4
new file mode 100755
index 0000000..936fce0
--- /dev/null
+++ b/algs4/extract-algs4
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+set -e
+
+cd src/java
+jar xf ../../algs4.jar
diff --git a/algs4/src/java/.gitignore b/algs4/src/java/.gitignore
index 6ab7a47..62c62db 100644
--- a/algs4/src/java/.gitignore
+++ b/algs4/src/java/.gitignore
@@ -1,28 +1,132 @@
+/AcyclicLP.java
+/AcyclicSP.java
+/Alphabet.java
+/Arbitrage.java
+/AssignmentProblem.java
 /Average.java
+/Bag.java
+/BellmanFordSP.java
+/BinaryDump.java
 /BinarySearch.java
+/BinarySearchST.java
+/Bipartite.java
+/BipartiteMatching.java
+/BlackFilter.java
+/BoruvkaMST.java
+/BoyerMoore.java
+/BreadthFirstDirectedPaths.java
+/BreadthFirstPaths.java
+/BST.java
+/BTree.java
 /Cat.java
+/CC.java
+/ClosestPair.java
+/CollisionSystem.java
+/Complex.java
 /Counter.java
-/RandomSeq.java
-/Shuffle.java
-/StaticSETofInts.java
-/Whitelist.java
-/Vector.java
+/Count.java
+/CPM.java
+/Cycle.java
 /Date.java
-/Transaction.java
-/Point2D.java
+/DeDup.java
+/DegreesOfSeparation.java
+/DepthFirstDirectedPaths.java
+/DepthFirstOrder.java
+/DepthFirstPaths.java
+/DepthFirstSearch.java
+/Digraph.java
+/DijkstraAllPairsSP.java
+/DijkstraSP.java
+/DirectedCycle.java
+/DirectedDFS.java
+/DirectedEdge.java
+/DoublingRatio.java
+/DoublingTest.java
+/Edge.java
+/EdgeWeightedDigraph.java
+/EdgeWeightedDirectedCycle.java
+/EdgeWeightedGraph.java
+/FarthestPair.java
+/FFT.java
+/FileIndex.java
+/FlowEdge.java
+/FlowNetwork.java
+/FordFulkerson.java
+/FrequencyCounter.java
+/GaussianElimination.java
+/Genome.java
+/GrahamScan.java
+/Graph.java
+/GREP.java
+/Heap.java
+/HexDump.java
+/Huffman.java
+/IndexMaxPQ.java
+/IndexMinPQ.java
+/Insertion.java
 /Interval1D.java
 /Interval2D.java
+/KMP.java
+/KosarajuSharirSCC.java
+/KruskalMST.java
+/KWIK.java
+/LazyPrimMST.java
+/LinearProbingHashST.java
+/LookupCSV.java
+/LookupIndex.java
+/LRS.java
+/LSD.java
+/LZW.java
+/MaxPQ.java
+/MergeBU.java
+/Merge.java
+/META-INF/MANIFEST.MF
+/MinPQ.java
+/MSD.java
+/Multiway.java
+/NFA.java
+/Particle.java
+/PictureDump.java
+/Point2D.java
+/PrimMST.java
+/Queue.java
+/Quick3string.java
+/Quick3way.java
+/QuickFindUF.java
+/Quick.java
+/QuickUnionUF.java
+/RabinKarp.java
+/RandomSeq.java
+/RedBlackBST.java
+/ResizingArrayQueue.java
 /ResizingArrayStack.java
+/RunLength.java
+/Selection.java
+/SeparateChainingHashST.java
+/SequentialSearchST.java
+/SET.java
+/Shell.java
+/Shuffle.java
+/Simplex.java
+/SparseVector.java
 /Stack.java
-/ResizingArrayQueue.java
-/Queue.java
-/Bag.java
+/StaticSETofInts.java
+/stdlib.jar
+/ST.java
 /Stopwatch.java
-/ThreeSum.java
+/SuffixArray.java
+/SymbolDigraph.java
+/SymbolGraph.java
 /ThreeSumFast.java
-/DoublingTest.java
-/DoublingRatio.java
-/QuickFindUF.java
-/QuickUnionUF.java
-/WeightedQuickUnionUF.java
+/ThreeSum.java
+/TopM.java
+/Topological.java
+/Transaction.java
+/TransitiveClosure.java
+/TrieST.java
+/TST.java
 /UF.java
+/Vector.java
+/WeightedQuickUnionUF.java
+/WhiteFilter.java
+/Whitelist.java