Add TSP Visualizer feature

Author: Kunwartejpal Sidhu

projects_registry.json

@@ -651,5 +651,22 @@
       "search"
     ],
     "path": "utilities/Pathfinding-Visualizer/Pathfinding-Visualizer.py"
+  },
+  {
+    "name": "TSP Visualizer",
+    "emoji": "🗺️",
+    "category": "utilities",
+    "difficulty": "advanced",
+    "description": "Visualize the Traveling Salesperson Problem (TSP) using Nearest Neighbor and Brute Force algorithms.",
+    "keywords": [
+      "tsp",
+      "visualizer",
+      "algorithm",
+      "salesperson",
+      "path",
+      "shortest",
+      "search"
+    ],
+    "path": "utilities/TSP-Visualizer/TSP-Visualizer.py"
   }
 ]

utilities/TSP-Visualizer/TSP-Visualizer.py

@@ -0,0 +1,169 @@
+import pygame
+import math
+import itertools
+import random
+import sys
+
+pygame.init()
+WIDTH, HEIGHT = 800, 600
+WIN = pygame.display.set_mode((WIDTH, HEIGHT))
+pygame.display.set_caption("TSP Visualizer")
+
+# Colors
+WHITE = (255, 255, 255)
+BLACK = (10, 10, 10)
+GRAY = (50, 50, 50)
+RED = (255, 100, 100)
+GREEN = (100, 255, 100)
+BLUE = (100, 100, 255)
+YELLOW = (255, 255, 100)
+
+font = pygame.font.SysFont("comicsansms", 20)
+small_font = pygame.font.SysFont("comicsansms", 15)
+
+def get_distance(p1, p2):
+    return math.hypot(p1[0] - p2[0], p1[1] - p2[1])
+
+def path_distance(nodes, order):
+    dist = 0
+    for i in range(len(order) - 1):
+        dist += get_distance(nodes[order[i]], nodes[order[i+1]])
+    if len(order) > 0:
+        dist += get_distance(nodes[order[-1]], nodes[order[0]])
+    return dist
+
+def draw_text(win, text, x, y, color=WHITE):
+    text_surface = font.render(text, True, color)
+    win.blit(text_surface, (x, y))
+
+def draw_nodes(win, nodes, order=[], current_edge=None, best_dist=0):
+    win.fill(BLACK)
+    
+    # Draw instructions
+    draw_text(win, "Click to add nodes | [R] Random | [C] Clear | [1] Nearest Neighbor | [2] Brute Force", 10, 10, GRAY)
+    draw_text(win, f"Nodes: {len(nodes)}", 10, 40, WHITE)
+    if best_dist > 0:
+        draw_text(win, f"Distance: {best_dist:.2f}", 10, 70, YELLOW)
+
+    # Draw the path
+    if len(order) > 1:
+        for i in range(len(order) - 1):
+            pygame.draw.line(win, GREEN, nodes[order[i]], nodes[order[i+1]], 2)
+        pygame.draw.line(win, GREEN, nodes[order[-1]], nodes[order[0]], 2)
+        
+    if current_edge:
+        pygame.draw.line(win, RED, current_edge[0], current_edge[1], 2)
+
+    # Draw nodes
+    for i, node in enumerate(nodes):
+        color = BLUE if i == 0 else WHITE
+        pygame.draw.circle(win, color, node, 6)
+        
+    pygame.display.update()
+
+def solve_nearest_neighbor(nodes):
+    if len(nodes) < 2: return
+    
+    unvisited = list(range(1, len(nodes)))
+    current = 0
+    order = [0]
+    
+    while unvisited:
+        # visualization step
+        for event in pygame.event.get():
+            if event.type == pygame.QUIT:
+                pygame.quit()
+                sys.exit()
+                
+        nearest = min(unvisited, key=lambda x: get_distance(nodes[current], nodes[x]))
+        
+        # Animate the connection being tested
+        draw_nodes(WIN, nodes, order, current_edge=(nodes[current], nodes[nearest]), best_dist=path_distance(nodes, order))
+        pygame.time.delay(100)
+        
+        order.append(nearest)
+        unvisited.remove(nearest)
+        current = nearest
+        
+    draw_nodes(WIN, nodes, order, best_dist=path_distance(nodes, order))
+
+def solve_brute_force(nodes):
+    if len(nodes) < 2: return
+    if len(nodes) > 10:
+        print("Too many nodes for brute force! (Max 10 recommended)")
+        return
+        
+    min_dist = float('inf')
+    best_order = []
+    
+    # fix the start node to 0 to reduce permutations by N
+    nodes_idx = list(range(1, len(nodes)))
+    count = 0
+    total = math.factorial(len(nodes_idx))
+    
+    for perm in itertools.permutations(nodes_idx):
+        for event in pygame.event.get():
+            if event.type == pygame.QUIT:
+                pygame.quit()
+                sys.exit()
+                
+        current_order = [0] + list(perm)
+        dist = path_distance(nodes, current_order)
+        if dist < min_dist:
+            min_dist = dist
+            best_order = current_order
+            
+        count += 1
+        if count % max(1, total // 100) == 0:  # animate periodically
+            draw_nodes(WIN, nodes, best_order, current_edge=(nodes[current_order[-1]], nodes[current_order[0]]), best_dist=min_dist)
+            
+    draw_nodes(WIN, nodes, best_order, best_dist=min_dist)
+
+def main():
+    nodes = []
+    order = []
+    best_dist = 0
+    run = True
+    
+    while run:
+        draw_nodes(WIN, nodes, order, best_dist=best_dist)
+        
+        for event in pygame.event.get():
+            if event.type == pygame.QUIT:
+                run = False
+                
+            if event.type == pygame.MOUSEBUTTONDOWN:
+                x, y = pygame.mouse.get_pos()
+                nodes.append((x, y))
+                order = []
+                best_dist = 0
+                
+            if event.type == pygame.KEYDOWN:
+                if event.key == pygame.K_c:
+                    nodes = []
+                    order = []
+                    best_dist = 0
+                elif event.key == pygame.K_r:
+                    nodes = []
+                    for _ in range(10):
+                        x = random.randint(50, WIDTH - 50)
+                        y = random.randint(100, HEIGHT - 50)
+                        nodes.append((x, y))
+                    order = []
+                    best_dist = 0
+                elif event.key == pygame.K_1:
+                    if len(nodes) > 1:
+                        solve_nearest_neighbor(nodes)
+                elif event.key == pygame.K_2:
+                    if len(nodes) > 1:
+                        if len(nodes) > 10:
+                            draw_text(WIN, "Too many nodes for Brute Force! Use <= 10.", 10, 100, RED)
+                            pygame.display.update()
+                            pygame.time.delay(2000)
+                        else:
+                            solve_brute_force(nodes)
+
+    pygame.quit()
+
+if __name__ == "__main__":
+    main()