implemented loadtriangle method:

src/main/java/NumberTriangle.java

@@ -88,8 +88,15 @@ public boolean isLeaf() {
      *
      */
     public int retrieve(String path) {
-        // TODO implement this method
-        return -1;
+        NumberTriangle current = this;
+        for (int i = 0; i < path.length(); i++) {
+            if (path.charAt(i) == 'l') {
+                current = current.left;
+            } else if (path.charAt(i) == 'r') {
+                current = current.right;
+            }
+        }
+        return current.getRoot();
     }
 
     /** Read in the NumberTriangle structure from a file.
@@ -110,19 +117,45 @@ public static NumberTriangle loadTriangle(String fname) throws IOException {
         BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
 
 
-        // TODO define any variables that you want to use to store things
+        List<List<NumberTriangle>> rows = new ArrayList<>();
 
         // will need to return the top of the NumberTriangle,
         // so might want a variable for that.
         NumberTriangle top = null;
 
         String line = br.readLine();
+        int rowNum = 0;
+
         while (line != null) {
 
             // remove when done; this line is included so running starter code prints the contents of the file
-            System.out.println(line);
 
-            // TODO process the line
+            line = line.trim();
+            if (!line.isEmpty()) {
+                String[] numbers = line.split("\\s+");
+                List<NumberTriangle> currentRow = new ArrayList<>();
+
+                for (String numStr : numbers) {
+                    int value = Integer.parseInt(numStr);
+                    currentRow.add(new NumberTriangle(value));
+                }
+                rows.add(currentRow);
+
+                if (rowNum == 0) {
+                    top = currentRow.get(0);
+                }
+
+                if (rowNum > 0) {
+                    List<NumberTriangle> prevRow = rows.get(rowNum - 1);
+                    for (int i = 0; i < prevRow.size(); i++) {
+                        NumberTriangle parent = prevRow.get(i);
+                        parent.setLeft(currentRow.get(i));
+                        parent.setRight(currentRow.get(i + 1));
+                    }
+                }
+
+                rowNum++;
+            }
 
             //read the next line
             line = br.readLine();