图 - Java实现无向带权图的邻接矩阵表示法
package com.lagou;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* @author 云梦归遥
* @date 2022/5/20 12:30
* @description 无向带权图 - 邻接矩阵法
*/
public class NoDirectionWeightTuMethod {
private List<Object> nodeList; // 存储所有节点的集合
private int[][] adjacencyMatrix; // 邻接矩阵
private int edge; // 边的数量
public NoDirectionWeightTuMethod(int num){
nodeList = new ArrayList<>(num);
adjacencyMatrix = new int[num][num];
edge = 0;
}
// 添加节点
public NoDirectionWeightTuMethod insert(Object node){
nodeList.add(node);
return this;
}
// 查找节点
public String select(Object node){
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append("【" + node + "】= ");
int index = nodeList.indexOf(node); // 获取索引
if (index >= 0){
// 节点存在
for (int i = 0; i < adjacencyMatrix.length; i++){
if (adjacencyMatrix[index][i] > 0){
stringBuilder.append("【<" + node + ", " + nodeList.get(i) + "> - weight: " + adjacencyMatrix[index][i] + "】 => ");
}
}
} else {
stringBuilder.append("null");
}
String result = stringBuilder.toString();
result = result.substring(0, result.lastIndexOf(" => "));
return result;
}
// 获取节点的个数
public int getNodeNum(){
return nodeList.size();
}
// 添加边（权重）
public NoDirectionWeightTuMethod addEdge(Object object1, Object object2, int weight){
if (nodeList.contains(object1) && nodeList.contains(object2)){
int index1 = nodeList.indexOf(object1);
int index2 = nodeList.indexOf(object2);
adjacencyMatrix[index1][index2] = weight;
adjacencyMatrix[index2][index1] = weight;
}
return this;
}
// 获取权重
public int getWeight(Object object1, Object object2){
int result = Integer.MAX_VALUE; // 默认 int 最大值
if (nodeList.contains(object1) && nodeList.contains(object2)){
int index1 = nodeList.indexOf(object1);
int index2 = nodeList.indexOf(object2);
result = adjacencyMatrix[index1][index2];
}
return result;
}
// 判断边是否存在
public boolean hasEdge(Object object1, Object object2){
boolean result = false;
if (nodeList.contains(object1) && nodeList.contains(object2)){
int index1 = nodeList.indexOf(object1);
int index2 = nodeList.indexOf(object2);
if (adjacencyMatrix[index1][index2] > 0){
result = true;
}
}
return result;
}
// 获取边的数量
public int getEdgeNum(Object object){
int num = Integer.MAX_VALUE;
if (nodeList.contains(object)){
num = 0;
int index = nodeList.indexOf(object);
for (int i = 0; i < adjacencyMatrix.length; i++){
if (adjacencyMatrix[index][i] > 0){
num++;
}
}
}
return num;
}
// 获取 邻接矩阵
public String getAdjacencyMatrix(){
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(" " + Arrays.toString(nodeList.toArray()) + "\n");
for (int i = 0; i < adjacencyMatrix.length; i++){
stringBuilder.append(nodeList.get(i) + " " + Arrays.toString(adjacencyMatrix[i]) + "\n");
}
return stringBuilder.toString();
}
}