Copy DFS experiment

main.cc

@@ -10,6 +10,7 @@
 #include <cstdlib>
 #include <ctime>
 #include <stack>
+#include <queue>
 
 using namespace std;
 
@@ -161,6 +162,7 @@ class World
 
 
 
+
 		// Depth-first search
 		// starting from tile number origin, find a path to tile number t
 		// return true if such a path exists, false otherwise
@@ -214,8 +216,85 @@ class World
 			} while (!targetIsReached && !open.empty());
 
 			// Remove origin and target
-			discovered.pop_front();
-			discovered.pop_back();
+			if (!discovered.empty()) {
+				discovered.pop_front();
+
+				if (!discovered.empty())
+					discovered.pop_back();
+			}
+
+			// Build path
+			if (targetIsReached) {
+				do {
+					path.push_back(current);
+					current = previous[current];
+				} while (current != origin);
+
+				path.pop_front();
+			}
+
+			return targetIsReached;
+		} 
+
+		// Breadth-first search
+		// starting from tile number origin, find a path to tile number t
+		// return true if such a path exists, false otherwise
+		// if it exists the path is given in variable path (hence the reference &)
+		const bool bfs(unsigned int origin, unsigned int target, list<unsigned int>& path, list<unsigned int>& discovered)
+		{
+			bool targetIsReached = false;
+
+			bool explored[size];
+			unsigned int previous[size];
+
+			for (unsigned int k(0); k < size; k ++) {
+				explored[k] = false;
+				previous[k] = k;
+			}
+
+			explored[origin] = true;
+
+
+			stack<unsigned int> open;
+			open.push(origin);
+
+			int current;
+			int neighbour;
+			unsigned int succs[4];
+			unsigned int nbSuccs;
+
+			do {
+				current = open.top();
+				open.pop();
+
+				nbSuccs = successors(current, succs);
+
+				for (unsigned int i(0); i < nbSuccs; i++) {
+					neighbour = succs[i];
+
+					if (!explored[neighbour]) {
+						open.push(neighbour);
+						previous[neighbour] = current;
+					}
+				}
+
+				// Current tile is now processed
+				explored[current] = true;
+
+				discovered.push_back(current);
+
+				// Stop if target found
+				targetIsReached = (current == target);
+
+			} while (!targetIsReached && !open.empty());
+
+			// Remove origin and target
+			if (!discovered.empty()) {
+				discovered.pop_front();
+
+				if (!discovered.empty())
+					discovered.pop_back();
+			}
 
 			// Build path
 			if (targetIsReached) {
@@ -247,7 +326,7 @@ class World
 				cout << "FAILURE ..." << endl;
 
 			cout << discovered.size() << " tiles discovered;" << endl;
-			cout << path.size() << " path length.";
+			cout << path.size() << " path length." << endl;
 		}
 };
 
@@ -271,15 +350,25 @@ int main()
 	w.markOne(end, TARGET);
 	w.display();
 
-	// Find a path with Depth-First Search
+	// 1
+	cout << endl << "Depth-First Search" << endl;
+
 	World dfsWorld(w);
 	list<unsigned int> dfsPath;
 	list<unsigned int> dfsDiscovered;
-	bool exitFound = dfsWorld.dfs(start, end, dfsPath, dfsDiscovered);
+	bool dfsExitFound = dfsWorld.dfs(start, end, dfsPath, dfsDiscovered);
 
-	// Display DFS
-	cout << endl << "Depth-First Search" << endl;
-	dfsWorld.showResults(exitFound, dfsDiscovered, dfsPath);
+	dfsWorld.showResults(dfsExitFound, dfsDiscovered, dfsPath);
+
+	// 2
+	cout << endl << "Breadth-First Search" << endl;
+
+	World bfsWorld(w);
+	list<unsigned int> bfsPath;
+	list<unsigned int> bfsDiscovered;
+	bool bfsExitFound = bfsWorld.bfs(start, end, bfsPath, bfsDiscovered);
+
+	bfsWorld.showResults(bfsExitFound, bfsDiscovered, bfsPath);
 
 	// End
 	return 0;