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prim.py (2751B)

      1 import pygame
      2 import heapq
      3 import random
      4 import math
      5 
      6 pygame.init()
      7 
      8 display = pygame.display.set_mode((5120,1440))
      9 
     10 VERTICES = 10000
     11 EDGES = 100000
     12 
     13 white = (255, 255, 255)
     14 red = (255, 0, 0)
     15 black = (0, 0, 0)
     16 grey = (100,100,100)
     17 light_grey = (50,50,50)
     18 
     19 
     20 class Vertex():
     21     def __init__(self, x, y):
     22         self.x = x
     23         self.y = y
     24         self.visited = False
     25     def draw_vertex(self,display):
     26         if self.visited:
     27             pygame.draw.circle(display, white, (self.x,self.y), 5)
     28         else:
     29             pygame.draw.circle(display, grey, (self.x,self.y), 5)
     30 class Edge():
     31     def __init__(self, v1, v2):
     32         self.v1 = v1
     33         self.v2 = v2
     34         self.dist = math.sqrt(((v1.x - v2.x) ** 2) + ((v1.y - v2.y) ** 2))
     35     def draw_edge(self,display, c):
     36         pygame.draw.line(display, c, (self.v1.x,self.v1.y), (self.v2.x,self.v2.y), 1)
     37 
     38     def __lt__(self,otr):
     39         return self.dist < otr.dist
     40 
     41 
     42 graph = {}
     43 
     44 for i in range(0,VERTICES):
     45     x = random.random() * 5120
     46     y = random.random() * 1440
     47     graph[Vertex(x,y)] = []
     48 
     49 
     50 edge_list = []
     51 keys = list(graph.keys())
     52 
     53 for i in range(0,EDGES):
     54     k1 = None
     55     k2 = None
     56     while k1 == k2:
     57         k1 = random.choice(keys)
     58         k2 = random.choice(keys)
     59 
     60     edge = Edge(k1,k2)
     61     graph[k1].append(edge)
     62     graph[k2].append(edge)
     63     edge_list.append(edge)
     64 
     65 
     66 edge_heap = []
     67 visited_vertices = set()
     68 
     69 
     70 start = random.choice(keys)
     71 start.visited = True
     72 visited_vertices.add(start)
     73 for edge in graph[start]:
     74     heapq.heappush(edge_heap, edge)
     75 
     76 
     77 first = True
     78 
     79 to_draw_vert = []
     80 to_draw_edge = []
     81 
     82 while True:
     83     for event in pygame.event.get():
     84         if event.type == pygame.QUIT:
     85             pygame.quit()
     86             quit()
     87 
     88     if first:
     89         display.fill(black)
     90 
     91         for edge in edge_list:
     92             edge.draw_edge(display, light_grey)
     93         first = False
     94 
     95         for vertex in graph:
     96             vertex.draw_vertex(display)
     97 
     98     for edge in to_draw_edge:
     99         edge.draw_edge(display, white)
    100     for vert in to_draw_vert:
    101         vert.draw_vertex(display)
    102 
    103     to_draw_vert = []
    104     to_draw_edge = []
    105 
    106 
    107     item = None
    108     while edge_heap:
    109         candidate = heapq.heappop(edge_heap)
    110         if (candidate.v1 in visited_vertices) != (candidate.v2 in visited_vertices):
    111             item = candidate
    112             break
    113 
    114     if item is None:
    115         break
    116 
    117     new_vertex = item.v2 if item.v1 in visited_vertices else item.v1
    118     visited_vertices.add(new_vertex)
    119     new_vertex.visited = True
    120 
    121     to_draw_vert.append(new_vertex)
    122     to_draw_edge.append(item)
    123 
    124     for edge in graph[new_vertex]:
    125         if not edge.v1 in visited_vertices or not edge.v2 in visited_vertices:
    126             heapq.heappush(edge_heap, edge)
    127 
    128     pygame.display.update()