fix possible hash bug in 8puzzle. explicitly set c++11. fix some warnings

Author: justinhj

cpp/8puzzle.cpp

@@ -345,9 +345,7 @@ size_t PuzzleState::Hash()
 	{
 		stream << tiles[i];
 	}
-	size_t state_digits;
-	stream >> state_digits;
-	return hash<size_t>{}(state_digits);
+  return std::hash<std::string>{}(stream.str());
 }
 
 void PuzzleState::PrintNodeInfo()

cpp/findpath.cpp

@@ -8,14 +8,14 @@
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-using namespace std;
-
-#include "stlastar.h" // See header for copyright and usage information
-
 #include <iostream>
 #include <stdio.h>
 #include <math.h>
 
+using namespace std;
+
+#include "stlastar.h" // See header for copyright and usage information
+
 #define DEBUG_LISTS 0
 #define DEBUG_LIST_LENGTHS_ONLY 0
 

cpp/makefile

@@ -1,19 +1,25 @@
 all : 8puzzle findpath minpathbucharest tests
 
+# Set the C++ compiler to g++
+CXX = g++
+
+# Set some common C++ flags
+CXXFLAGS = -std=c++11 -Wall
+
 clean :
 	rm 8puzzle findpath minpathbucharest tests
 
 minpathbucharest : min_path_to_Bucharest.cpp stlastar.h
-	g++ -Wall min_path_to_Bucharest.cpp -o minpathbucharest
+	$(CXX) $(CXXFLAGS) min_path_to_Bucharest.cpp -o minpathbucharest
 
 8puzzle : 8puzzle.cpp stlastar.h
-	g++ -Wall 8puzzle.cpp -o 8puzzle
+	$(CXX) $(CXXFLAGS) -Wall 8puzzle.cpp -o 8puzzle
 
 findpath : findpath.cpp stlastar.h
-	g++ -Wall findpath.cpp -o findpath
+	$(CXX) $(CXXFLAGS) findpath.cpp -o findpath
 
 tests : tests.cpp 8puzzle findpath minpathbucharest
-	g++ -Wall tests.cpp -o tests
+	$(CXX) $(CXXFLAGS) tests.cpp -o tests
 
 test: tests
 	./tests

cpp/min_path_to_Bucharest.cpp

@@ -18,14 +18,15 @@
 // mention that the algorithm does some backtracking because the heuristic is not accurate (yet still admissable).
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-using namespace std;
-
-#include "stlastar.h"
 #include <iostream>
 #include <string>
 #include <vector>
 #include <stdio.h>
 
+using namespace std;
+
+#include "stlastar.h"
+
 #define DEBUG_LISTS 0
 #define DEBUG_LIST_LENGTHS_ONLY 0
 

cpp/stlastar.h

@@ -81,7 +81,7 @@ template <class UserState> class AStarSearch
 			Node *parent; // used during the search to record the parent of successor nodes
 			Node *child; // used after the search for the application to view the search in reverse
 
-			float g; // cost of this node + it's predecessors
+			float g; // cost of this node + its predecessors
 			float h; // heuristic estimate of distance to goal
 			float f; // sum of cumulative cost of predecessors and self and heuristic
 
@@ -321,8 +321,9 @@ template <class UserState> class AStarSearch
 						continue;
 					}
 				}
+        typename unordered_set<Node*, NodeHash, NodeEqual>::iterator closedlist_result;
 
-				auto closedlist_result = m_ClosedList.find(*successor);
+        closedlist_result = m_ClosedList.find(*successor);
 
 				if( closedlist_result != m_ClosedList.end() )
 				{