diff --git a/.gitignore b/.gitignore
index c1bf33e..70a8511 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,8 +2,41 @@
 *.fasl
 *.pyc
 *.o
+*.pdf
+.d
 
 # ignore build systems
 .ninja_deps
 .ninja_log
 *.ninja
+
+# editor crap
+.vscode/*
+!.vscode/settings.json
+
+# data files
+ods/data/corpus.txt
+ods/data/cpp
+ods/data/ods-cpp.tgz
+ods/data/ods-cpp.pdf
+
+# autotools junk files
+.deps
+Makefile
+Makefile.in
+aclocal.m4
+autom4te.cache/
+compile
+config.*
+configure
+depcomp
+install-sh
+libtool
+ltmain.sh
+m4/
+missing
+
+ch??ex??
+*_test
+*.la
+*_bench
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..11ba3e7
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+	"cppcheck.includePaths": ["${workspaceRoot}/ods/src"]
+}
\ No newline at end of file
diff --git a/ods/.gitignore b/ods/.gitignore
deleted file mode 100644
index c61ba60..0000000
--- a/ods/.gitignore
+++ /dev/null
@@ -1,26 +0,0 @@
-# data files
-data/corpus.txt
-data/cpp
-data/ods-cpp.tgz
-
-# autotools junk files
-.deps
-Makefile
-Makefile.in
-aclocal.m4
-autom4te.cache/
-compile
-config.*
-configure
-depcomp
-install-sh
-libtool
-ltmain.sh
-m4/
-missing
-
-# build artifacts
-src/*.o
-src/ch??ex??
-src/*.la
-src/*_bench
diff --git a/ods/data/Makefile.am b/ods/data/Makefile.am
index dbd6f14..e324dbe 100644
--- a/ods/data/Makefile.am
+++ b/ods/data/Makefile.am
@@ -1,4 +1,4 @@
-pkgdata_DATA = corpus.txt ods-cpp/main.cpp
+pkgdata_DATA = corpus.txt ods-cpp/main.cpp ods-cpp.pdf
 
 corpus.txt: corpus.txt.gz
 	gzip -d -k $@.gz
@@ -10,3 +10,9 @@ ODS_SAMPLE_CODE_URL :=		http://opendatastructures.org/ods-cpp.tgz
 ods-cpp.tgz:
 	if command -v curl 2>&1 > /dev/null ; then curl -L -O $(ODS_SAMPLE_CODE_URL) ; \
 	elif command -v curl 2>&1 > /dev/null ; then wget $(ODS_SAMPLE_CODE_URL) ; fi
+
+ODS_PDF_URL :=			http://opendatastructures.org/ods-cpp.pdf
+ods-cpp.pdf:
+	if command -v curl 2>&1 > /dev/null ; then curl -L -O $(ODS_PDF_URL) ; \
+	elif command -v curl 2>&1 > /dev/null ; then wget $(ODS_PDF_URL) ; fi
+
diff --git a/ods/src/array_test.cc b/ods/src/array_test.cc
index 54db1c5..ef3c8c8 100644
--- a/ods/src/array_test.cc
+++ b/ods/src/array_test.cc
@@ -1,6 +1,8 @@
 #include <iostream>
 #include <ods/array.h>
+#include <ods/array_stack.h>
 using namespace std;
+using namespace ods;
 
 int
 main(void)
@@ -10,5 +12,15 @@ main(void)
 	cout << "a[0] " << a[0] << endl;
 	
 	b = a;
-	cout << "a[0] " << a[0] << endl;
-}
\ No newline at end of file
+	cout << "b[0] " << b[0] << endl;
+
+	ArrayStack<int>	as(5);
+	for (int i = 0; i < 3; i++) {
+		as.set(i, i+1);
+	}
+	as.add(1, 42);
+	cout << "as[0] " << as.get(0) << endl;
+	cout << "as[1] " << as.get(1) << endl;
+	as.remove(0);
+	cout << "as[0] " << as.get(0) << endl;
+}
diff --git a/ods/src/ods/array.h b/ods/src/ods/array.h
index fe1a55b..dd56ecc 100644
--- a/ods/src/ods/array.h
+++ b/ods/src/ods/array.h
@@ -1,6 +1,7 @@
 #ifndef __ODS_ODS_ARRAY__
 #define __ODS_ODS_ARRAY__
 
+#include <cassert>
 #include <cstdint>
 
 namespace ods {
@@ -8,35 +9,34 @@ namespace ods {
 template<typename T>
 class Array {
 public:
-	Array(int len) : length(len) { a = new T[length]; }
+	T	*a;
+	int	 length;
+
+	Array(int len) : a(new T[len]), length(len) {}
+
 	T& operator[](int i) {
-		assert(i >= 0 && static_cast<std::size_t>(i) < length);
+		assert(i >= 0 && i < length);
 		return a[i];
 	}
+
 	Array<T>& operator=(Array<T> &rhs) {
 		if (a != nullptr) {
-			delete a;
+			delete[] a;
 		}
 		
 		a = rhs.a;
 		
 		// I don't understand why this is done, but it's how the book defines it.
 		rhs.a = nullptr;
-		
-		// I put this in to prevent segfaults.
-		rhs.length = 0;
-
 
 		length = rhs.length;
+
+		// I put this in to prevent segfaults.
+		rhs.length = 0;
 		return *this;
 	}
-	
-	std::size_t	size(void) { return length; }
-private:
-	T		*a;
-	std::size_t	 length;
 };
 
 } // namespace ods
 
-#endif // __ODS_ODS_ARRAY__
\ No newline at end of file
+#endif // __ODS_ODS_ARRAY__
diff --git a/ods/src/ods/array_stack.h b/ods/src/ods/array_stack.h
index 0b4931b..952a0c5 100644
--- a/ods/src/ods/array_stack.h
+++ b/ods/src/ods/array_stack.h
@@ -1,18 +1,58 @@
 #ifndef __ODS_ODS_ARRAY_STACK__
 #define __ODS_ODS_ARRAY_STACK__
 
+#include <iostream>
+#include <ods/array.h>
 
 namespace ods {
 
 
 template<typename T>
 class ArrayStack {
-	int size(void) { return static_cast<int>(this->a->size()); }
+public:
+	ArrayStack(int len) : n(0), a(Array<T>(len)) {}
+	int size(void) { return a.length; }
+	T get(int i) { return a[i]; }
+	T set(int i, T x) { 
+		T y = a[i];
+		a[i] = x;
+		return y;
+	}
+
+	void add(int i, T x) {
+		if (n+1 > a.length) {
+			resize();
+		}
+
+		for (int j = n; j > i; j--) {
+			a[j] = a[j-1];
+		}
+
+		a[i] = x;
+		n++;
+	}
+
+	T remove(int i) {
+		T x = a[i];
+		for (int j = i; j < (n-1); j++) {
+			std::cout << j << "\t" << i << "\t" << a[j] << std::endl;
+			a[j] = a[j+1];
+		}
+		n--;
+
+		if (a.length > 3*n) {
+			resize();
+		}
+
+		return x;
+	}
+
+	void resize(void) {}
 private:
-	Array<T>	a;
 	int		n;
-}
+	Array<T>	a;
+};
 
 } // namespace ods
 
-#endif // __ODS_ODS_ARRAY_STACK__
\ No newline at end of file
+#endif // __ODS_ODS_ARRAY_STACK__