Add exercises

exercises/task01/hello.cpp

@@ -0,0 +1,6 @@
+#include <iostream>
+
+int main()
+{
+	std::cout << "Hello World" << std::endl;
+}

exercises/task01/hello_boost.cpp

@@ -0,0 +1,11 @@
+#include <iostream>
+
+#include <boost/algorithm/string/replace.hpp>
+
+int main()
+{
+	std::string s = "foo bar";
+	boost::replace_all(s, "foo", "Hello");
+	boost::replace_all(s, "bar", "World");
+	std::cout << s << std::endl;
+}