块自适应算法smi代码
时间: 2023-05-17 07:01:20 浏览: 159
块自适应算法(Block Self-Adaptive Algorithm)是一种用于解决无约束组合优化问题的启发式算法。其主要思路是将问题划分为若干个块,每个块内部使用不同的局部搜索算法来寻找最优解,并根据不同块的表现来自适应地调整搜索策略和参数,以达到更优的结果。
以下是块自适应算法的SMI(Selective Memory Insertion)代码实现:
```python
def block_self_adaptive_algorithm():
# 初始化参数
blockSize = 10
maxIteration = 200
memorySize = 10
searchMethods = ['hill_climbing', 'simulated_annealing', 'genetic_algorithm']
bestSolution = None
bestFitness = float('-inf')
results = []
# 初始化块
blocks = []
for i in range(blockSize):
block = {'searchMethod': searchMethods[i % len(searchMethods)],
'currentSolution': None,
'currentFitness': None,
'bestSolution': None,
'bestFitness': float('-inf'),
'memory': []}
blocks.append(block)
# 开始搜索
for iteration in range(maxIteration):
for i in range(blockSize):
# 在当前块中进行局部搜索
searchMethod = blocks[i]['searchMethod']
currentSolution = blocks[i]['currentSolution']
currentFitness = blocks[i]['currentFitness']
newSolution, newFitness = perform_local_search(searchMethod, currentSolution, currentFitness)
# 记录搜索结果
blocks[i]['currentSolution'] = newSolution
blocks[i]['currentFitness'] = newFitness
if newFitness > blocks[i]['bestFitness']:
blocks[i]['bestSolution'] = newSolution
blocks[i]['bestFitness'] = newFitness
# 将搜索结果加入记忆
memory = blocks[i]['memory']
memory.append((newSolution, newFitness))
if len(memory) > memorySize:
memory.pop(0)
# 从记忆中选择一个好的解作为下次搜索的起点
solutions = [x[0] for x in memory]
fitnesses = [x[1] for x in memory]
maxIndex = fitnesses.index(max(fitnesses))
blocks[i]['currentSolution'] = solutions[maxIndex]
blocks[i]['currentFitness'] = fitnesses[maxIndex]
# 记录全局最优解
for i in range(blockSize):
if blocks[i]['bestFitness'] > bestFitness:
bestSolution = blocks[i]['bestSolution']
bestFitness = blocks[i]['bestFitness']
results.append(bestFitness)
return results
```
该代码首先初始化了块的参数,然后创建了若干个块,每个块使用不同的搜索算法来进行局部搜索,并将搜索结果记录到记忆中。最后,在每次迭代结束后,从所有块中选出最好的解作为全局最优解,并将其记录在results中。
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