From e1702573c0d81d6e8b86c2da5e29c1eb18eb13e8 Mon Sep 17 00:00:00 2001
From: vishwesh <vishwesh103@gmail.com>
Date: Tue, 28 Nov 2023 14:12:51 -0700
Subject: [PATCH] Add strategy pattern to graph search functionality.

---
 src/main/java/Context.java        | 16 ++++++++++++++++
 src/main/java/GraphData.java      |  9 +++++----
 src/main/java/GraphSearch.java    | 23 ++++++++++++++---------
 src/main/java/SearchStrategy.java |  6 ++++++
 4 files changed, 41 insertions(+), 13 deletions(-)
 create mode 100644 src/main/java/Context.java
 create mode 100644 src/main/java/SearchStrategy.java

diff --git a/src/main/java/Context.java b/src/main/java/Context.java
new file mode 100644
index 0000000..93608ce
--- /dev/null
+++ b/src/main/java/Context.java
@@ -0,0 +1,16 @@
+import org.jgrapht.Graph;
+import org.jgrapht.graph.DefaultEdge;
+
+public class Context {
+    SearchStrategy strategy;
+    Context(SearchStrategy strategy)
+    {
+        this.strategy = strategy;
+    }
+
+    Path searchByStrategy(){
+        strategy.selectAlgorithm();
+        strategy.executeAlgorithm();
+        return strategy.getPath();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/GraphData.java b/src/main/java/GraphData.java
index 108883a..de639b5 100644
--- a/src/main/java/GraphData.java
+++ b/src/main/java/GraphData.java
@@ -141,18 +141,19 @@ public boolean addEdge(String srcLabel, String dstLabel) {
     }
 
     public Path GraphSearch(String src, String dst, Algorithm algo) {
-        GraphSearchAlgorithm searchAlgorithm;
+        SearchStrategy strategy;
         switch(algo) {
             case BFS:
-                searchAlgorithm = new BFS(src, dst, graphObject);
+                strategy = new BFS(src, dst, graphObject);
                 break;
             case DFS:
-                searchAlgorithm = new DFS(src, dst, graphObject);
+                strategy = new DFS(src, dst, graphObject);
                 break;
             default:
                 throw new IllegalArgumentException("Invalid choice of algorithm");
         }
-        return searchAlgorithm.graphSearch();
+        Context searchContext = new Context(strategy);
+        return searchContext.searchByStrategy();
     }
     public void removeEdge(String srcLabel, String dstLabel) throws Exception {
         DefaultEdge edgeexisting = graphObject.getEdge(srcLabel, dstLabel);
diff --git a/src/main/java/GraphSearch.java b/src/main/java/GraphSearch.java
index 72eb14a..3f4eacf 100644
--- a/src/main/java/GraphSearch.java
+++ b/src/main/java/GraphSearch.java
@@ -33,7 +33,7 @@ public Path graphSearch() {
     protected abstract Path getPath();
 }
 
-class BFS extends GraphSearchAlgorithm {
+class BFS extends GraphSearchAlgorithm implements SearchStrategy {
     private LinkedList<String> queue;
 
     public BFS(String src, String dst, Graph graph) {
@@ -41,13 +41,14 @@ public BFS(String src, String dst, Graph graph) {
         queue = new LinkedList<>();
     }
 
-    protected void selectAlgorithm() {
+    @Override
+    public void selectAlgorithm() {
         System.out.println("Using BFS");
         visited.put(source, true);
         queue.add(source);
     }
-
-    protected void executeAlgorithm() {
+    @Override
+    public void executeAlgorithm() {
         while (!queue.isEmpty()) {
             String src = queue.poll();
             if (src.equals(destination)) {
@@ -64,7 +65,8 @@ protected void executeAlgorithm() {
         }
     }
 
-    protected Path getPath() {
+    @Override
+    public Path getPath() {
         String node = destination;
         path.add(node);
         if (visited.get(destination) != null) {
@@ -81,7 +83,7 @@ protected Path getPath() {
     }
 }
 
-class DFS extends GraphSearchAlgorithm {
+class DFS extends GraphSearchAlgorithm implements SearchStrategy {
     private Stack<String> stack;
 
     public DFS(String src, String dst, Graph graph) {
@@ -89,13 +91,15 @@ public DFS(String src, String dst, Graph graph) {
         stack = new Stack<>();
     }
 
-    protected void selectAlgorithm() {
+    @Override
+    public void selectAlgorithm() {
         System.out.println("Using DFS");
         visited.put(source, true);
         stack.push(source);
     }
 
-    protected void executeAlgorithm() {
+    @Override
+    public void executeAlgorithm() {
         while (!stack.isEmpty()) {
             String src = stack.pop();
             if (src.equals(destination)) {
@@ -112,7 +116,8 @@ protected void executeAlgorithm() {
         }
     }
 
-    protected Path getPath() {
+    @Override
+    public Path getPath() {
         String node = destination;
         path.add(node);
         if (visited.get(destination) != null) {
diff --git a/src/main/java/SearchStrategy.java b/src/main/java/SearchStrategy.java
new file mode 100644
index 0000000..251dba3
--- /dev/null
+++ b/src/main/java/SearchStrategy.java
@@ -0,0 +1,6 @@
+public interface SearchStrategy {
+    void selectAlgorithm();
+    void executeAlgorithm();
+    Path getPath();
+}
+