adding cs142 code

cs142/lab10/arena.h

@@ -0,0 +1,23 @@
+#ifndef __ARENA_H__
+#define __ARENA_H__
+
+#include <vector>
+#include "ArenaInterface.h"
+
+class arena : public ArenaInterface {
+    private:
+        std::vector<FighterInterface *> fighters;
+        bool contains(string name);
+    public:
+        arena(){}
+        ~arena();
+		bool addFighter(string info);
+		bool removeFighter(string name);
+		FighterInterface * getFighter(string name);
+		int getSize();
+
+    friend ostream & operator<<(ostream &, arena &);
+};
+
+
+#endif