markus

src/main/java/NumberTriangle.java

@@ -88,10 +88,21 @@ public boolean isLeaf() {
      *
      */
     public int retrieve(String path) {
-        // TODO implement this method
-        return -1;
+        NumberTriangle current = this;
+        for (char c : path.toCharArray()) {
+            if (c == 'l') {
+                current = current.left;
+            } else if (c == 'r') {
+                current = current.right;
+            } else {
+                return -1;
+            }
+            if (current == null) {
+                return -1;
+            }
+        }
+        return current.root;
     }
-
     /** Read in the NumberTriangle structure from a file.
      *
      * You may assume that it is a valid format with a height of at least 1,
@@ -103,34 +114,51 @@ public int retrieve(String path) {
      * @return the topmost NumberTriangle object in the NumberTriangle structure read from the specified file
      * @throws IOException may naturally occur if an issue reading the file occurs
      */
+    //minor update for PR
     public static NumberTriangle loadTriangle(String fname) throws IOException {
         // open the file and get a BufferedReader object whose methods
         // are more convenient to work with when reading the file contents.
         InputStream inputStream = NumberTriangle.class.getClassLoader().getResourceAsStream(fname);
-        BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
-
-
-        // TODO define any variables that you want to use to store things
+        if (inputStream == null) {
+            throw new FileNotFoundException("File not found: " + fname);
+        }
 
-        // will need to return the top of the NumberTriangle,
-        // so might want a variable for that.
+        BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
+        java.util.List<java.util.List<NumberTriangle>> levels = new java.util.ArrayList<>();
         NumberTriangle top = null;
 
         String line = br.readLine();
-        while (line != null) {
+        while (line != null && !line.trim().isEmpty()) {
 
-            // remove when done; this line is included so running starter code prints the contents of the file
-            System.out.println(line);
+            String[] parts = line.trim().split("\\s+");
 
-            // TODO process the line
+            java.util.List<NumberTriangle> currentRow = new java.util.ArrayList<>();
 
-            //read the next line
+            for (String p : parts) {
+                currentRow.add(new NumberTriangle(Integer.parseInt(p)));
+            }
+
+            if (!levels.isEmpty()) {
+                java.util.List<NumberTriangle> prevRow = levels.get(levels.size() - 1);
+                for (int i = 0; i < prevRow.size(); i++) {
+                    prevRow.get(i).setLeft(currentRow.get(i));
+                    prevRow.get(i).setRight(currentRow.get(i + 1));
+                }
+            }
+
+            levels.add(currentRow);
             line = br.readLine();
         }
         br.close();
+
+        if (!levels.isEmpty()) {
+            top = levels.get(0).get(0);
+        }
+
         return top;
     }
 
+
     public static void main(String[] args) throws IOException {
 
         NumberTriangle mt = NumberTriangle.loadTriangle("input_tree.txt");
@@ -142,3 +170,4 @@ public static void main(String[] args) throws IOException {
         System.out.println(mt.getRoot());
     }
 }
+