Update Bulgarian Solitaire

Modify the Bulgarian Solitaire component to send double-clicked boxes to the last-used column.

src/components/BulgarianSolitaire.tsx

@@ -23,6 +23,7 @@ const BulgarianSolitaire: React.FC<BulgarianSolitaireProps> = ({ showSocialShare
   const [isComplete, setIsComplete] = useState(false);
   const [highlightedBoxes, setHighlightedBoxes] = useState<Set<number>>(new Set());
   const [isAnimating, setIsAnimating] = useState(false);
+  const [lastUsedColumn, setLastUsedColumn] = useState<number | null>(null);
 
   const totalBoxes = (n * (n + 1)) / 2;
 
@@ -72,6 +73,8 @@ const BulgarianSolitaire: React.FC<BulgarianSolitaireProps> = ({ showSocialShare
       b.id === draggedBox ? { ...b, columnIndex } : b
     ));
 
+    // Track last used column
+    setLastUsedColumn(columnIndex);
     setDraggedBox(null);
   };
 
@@ -99,15 +102,28 @@ const BulgarianSolitaire: React.FC<BulgarianSolitaireProps> = ({ showSocialShare
     const box = boxes.find(b => b.id === boxId);
     if (!box || box.columnIndex === null) return;
 
-    // Remove from column
+    // Remove from current column
     setColumns(prev => prev.map((col, idx) => 
       idx === box.columnIndex ? col.filter(id => id !== boxId) : col
     ));
 
-    // Return to container
-    setBoxes(prev => prev.map(b => 
-      b.id === boxId ? { ...b, columnIndex: null } : b
-    ));
+    // Move to last used column or container if no last used column
+    if (lastUsedColumn !== null && lastUsedColumn !== box.columnIndex) {
+      // Add to last used column
+      setColumns(prev => prev.map((col, idx) => 
+        idx === lastUsedColumn ? [...col, boxId] : col
+      ));
+      
+      // Update box location
+      setBoxes(prev => prev.map(b => 
+        b.id === boxId ? { ...b, columnIndex: lastUsedColumn } : b
+      ));
+    } else {
+      // Return to container if no last used column or same as current
+      setBoxes(prev => prev.map(b => 
+        b.id === boxId ? { ...b, columnIndex: null } : b
+      ));
+    }
   };
 
   const sleep = (ms: number) => new Promise(resolve => setTimeout(resolve, ms));
@@ -309,7 +325,7 @@ const BulgarianSolitaire: React.FC<BulgarianSolitaireProps> = ({ showSocialShare
                       ? 'bg-red-500 text-white shadow-lg scale-110' 
                       : 'bg-primary text-primary-foreground hover:bg-primary/80'
                   } ${isAnimating && highlightedBoxes.has(boxId) ? 'animate-pulse' : ''}`}
-                  title="Drag to move or double-click to return to container"
+                  title="Drag to move or double-click to move to last-used column"
                 >
                 </div>
               ))}
@@ -347,7 +363,7 @@ const BulgarianSolitaire: React.FC<BulgarianSolitaireProps> = ({ showSocialShare
           <li>Choose a value for n (2-6) using the slider</li>
           <li>Drag the {totalBoxes} boxes from the container into any of the columns</li>
           <li>Drag boxes between columns to rearrange them as needed</li>
-          <li>Drag boxes back to the container or double-click any box in a column to return it</li>
+          <li>Drag boxes back to the container or double-click any box in a column to move it to the last-used column</li>
           <li>Once all boxes are placed in columns, click "Play" to start the simulation</li>
           <li>Watch as the algorithm takes one box from each non-empty column to form a new column</li>
           <li>The process continues until reaching the triangular configuration: columns of sizes 1, 2, 3, ..., n</li>