给出python代码,使用启发式算法解决一个结点数为50的旅行商问题
时间: 2023-03-07 12:53:33 浏览: 149
答:
# 导入需要的库
import numpy as np# 初始化结点数组
nodes = np.arange(50)# 定义一个路线
route = []# 启发式算法
# 首先从结点数组中选择一个节点作为起点
start_node = np.random.choice(nodes)
route.append(start_node)# 计算当前节点与所有其他节点的距离
distances = [np.linalg.norm(i - start_node) for i in nodes]# 从距离中选择最近的节点作为下一个节点
next_node = np.argmin(distances)
route.append(next_node)# 重复上述步骤,直到所有节点都被选择
while len(route) < 50:
# 计算当前节点与所有其他节点的距离
distances = [np.linalg.norm(i - next_node) for i in nodes if i not in route]
# 从距离中选择最近的节点作为下一个节点
next_node = np.argmin(distances)
route.append(next_node)# 返回最终的路线
print(route)
相关问题
给出python代码,使用启发式算法解决一个结点数为50的旅行商问题,最终将路线绘制为动画
答:import networkx as nx
import matplotlib.pyplot as plt
import numpy as np
from random import randint
import matplotlib.animation as animation
# 创建图
G = nx.Graph()
# 设置节点
G.add_nodes_from(range(50))
# 设置边,节点之间的距离
for i in range(50):
for j in range(50):
if i < j:
G.add_edge(i,j,weight=randint(1,10))
# 使用启发式算法求解旅行商问题
def TSP(G, start):
shortest_path = []
remain_node = list(G.nodes)
remain_node.remove(start)
current_node = start
while remain_node:
next_node = min(remain_node, key=lambda x: G[current_node][x]['weight'])
shortest_path.append([current_node, next_node])
remain_node.remove(next_node)
current_node = next_node
shortest_path.append([current_node, start])
return shortest_path
# 动画可视化
def animate(i):
plt.cla()
x = []
y = []
for n in shortest_path[i]:
x.append(G.nodes[n]['pos'][0])
y.append(G.nodes[n]['pos'][1])
plt.plot(x,y,'r-')
plt.scatter(x,y,s=100,c='b')
plt.text(x[1], y[1], '%d'%(i+1), fontsize=15)
shortest_path = TSP(G, 0)
fig = plt.figure(figsize=(8,8))
ax = fig.add_subplot(111)
x = []
y = []
for n in shortest_path:
x.append(G.nodes[n[0]]['pos'][0])
y.append(G.nodes[n[0]]['pos'][1])
plt.plot(x,y)
ani = animation.FuncAnimation(fig, animate,
frames=len(shortest_path), interval=200, repeat=False)
plt.show()
给出python代码,随机给出50个二维坐标点,使用启发式算法解决包含这50个点的旅行商问题,最终将路线绘制为动画
import random
import matplotlib.pyplot as plt
import numpy as np
from heuristics import * # 生成50个二维坐标点
points = []
for i in range(50):
x = random.randint(-50, 50)
y = random.randint(-50, 50)
points.append((x, y)) # 使用启发式算法解决旅行商问题
solution = nearest_neighbor_heuristic(points) # 将路径绘制为动画
fig, ax = plt.subplots()
ax.set_xlim(-50, 50)
ax.set_ylim(-50, 50)
ax.set_title('Travelling Salesman Solution') # 绘制所有坐标点
for point in points:
ax.scatter(point[0], point[1], s=4, c='k') # 绘制路径
for i in range(len(solution)):
x = [points[solution[i-1]][0], points[solution[i]][0]]
y = [points[solution[i-1]][1], points[solution[i]][1]]
ax.plot(x, y, c='b') # 动画效果
ani = animation.FuncAnimation(fig, animate, frames=len(solution), interval=500, repeat=False, blit=False)
plt.show()
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