Seemingly finish the assignment.

Makefile

@@ -1,7 +1,7 @@
 all: scan
 
 scan: main.cpp scanner.cpp parser.cpp
-	g++ main.cpp scanner.cpp parser.cpp -o scan
+	g++ -std=c++11 main.cpp scanner.cpp parser.cpp -o scan
 
 scanner.cpp: scanner.l
 	flex -o scanner.cpp scanner.l