spring boot实现基于蚁群算法的文件最短路径搜索
时间: 2023-11-21 20:05:06 浏览: 32
实现基于蚁群算法的文件最短路径搜索需要以下步骤:
1. 定义蚂蚁和路径的数据结构
```java
public class Ant {
private int id;
private int currentCity;
private List<Integer> tabuList;
private List<Integer> allowedCities;
private double tourLength;
}
public class Graph {
private int numOfCities;
private double[][] distances;
}
```
2. 初始化蚂蚁和距离矩阵
```java
public void initAnts() {
// 初始化蚂蚁
for (int i = 0; i < numAnts; i++) {
Ant ant = new Ant();
ant.setId(i);
ant.setTabuList(new ArrayList<Integer>());
ant.setAllowedCities(new ArrayList<Integer>());
for (int j = 0; j < numOfCities; j++) {
ant.getAllowedCities().add(j);
}
ant.setCurrentCity(random.nextInt(numOfCities));
ants.add(ant);
}
// 初始化距离矩阵
distances = new double[numOfCities][numOfCities];
for (int i = 0; i < numOfCities; i++) {
for (int j = 0; j < numOfCities; j++) {
distances[i][j] = graph.getDistances()[i][j];
}
}
}
```
3. 计算蚂蚁在当前城市到其他城市的概率
```java
public double calculateProbability(int i, int j) {
double pheromone = Math.pow(pheromones[i][j], alpha);
double distance = Math.pow(1.0 / distances[i][j], beta);
double sum = 0.0;
for (Integer city : ants.get(i).getAllowedCities()) {
sum += Math.pow(pheromones[i][city], alpha) * Math.pow(1.0 / distances[i][city], beta);
}
return (pheromone * distance) / sum;
}
```
4. 蚂蚁选择下一个城市并更新信息素
```java
public void moveAnts() {
for (Ant ant : ants) {
int currentCity = ant.getCurrentCity();
List<Integer> allowedCities = ant.getAllowedCities();
List<Double> probabilities = new ArrayList<Double>();
for (Integer city : allowedCities) {
probabilities.add(calculateProbability(currentCity, city));
}
int nextCity = rouletteWheelSelection(allowedCities, probabilities);
ant.getTabuList().add(currentCity);
ant.setTourLength(ant.getTourLength() + distances[currentCity][nextCity]);
ant.setCurrentCity(nextCity);
ant.getAllowedCities().remove(new Integer(nextCity));
updatePheromone(currentCity, nextCity, ant.getTourLength());
if (ant.getTabuList().size() == numOfCities) {
ant.setTourLength(ant.getTourLength() + distances[nextCity][ant.getTabuList().get(0)]);
ant.getTabuList().add(nextCity);
}
}
}
```
5. 更新信息素
```java
public void updatePheromone(int i, int j, double tourLength) {
double pheromone = Q / tourLength;
pheromones[i][j] = (1 - rho) * pheromones[i][j] + rho * pheromone;
pheromones[j][i] = pheromones[i][j];
}
```
6. 迭代搜索
```java
public void search() {
// 初始化
initAnts();
// 迭代搜索
for (int i = 0; i < numIterations; i++) {
moveAnts();
updateBest();
updatePheromoneTrail();
reInitAnts();
}
}
```
7. 部署到Spring Boot
将以上代码封装到一个类中,然后在Spring Boot中使用该类进行文件最短路径搜索。可以通过RESTful API让用户上传文件和指定起点、终点,然后返回最短路径。