多源最短路径（ Floyd算法）JAVA实现

多源最短路径（ Floyd算法）JAVA实现

package floyd;

public class Graph {
final int max=100;
/*
* 顶点节点
*/
public class VexNode{
int adjvex;
int data;
}

VexNode[] vexNodes;
int[] thevexs; //顶点集合
int[][] edges = new int[max][max]; //边集合

/*
* 创建图
*/
public void createGraph(Graph graph,int[][] A,int[] vexs) {
thevexs=vexs;
for (int i = 0; i < vexs.length; i++) {
for (int j = 0; j < vexs.length; j++) {
graph.edges[i][j] = A[i][j];
}
}
}

/*
* 输出图
*/
public void printGraph(Graph graph) {
for (int i = 0; i < graph.thevexs.length; i++) {
for (int j = 0; j < graph.thevexs.length; j++) {
//没有路径则输出/
if (graph.edges[i][j]==1000) {
System.out.printf("%4s","/");

}else {
System.out.printf("%4d",graph.edges[i][j]);
}

}
System.out.println("\n");
}
}

}

package floyd;

public class Floyd {
final int max = 100;
final int INF = 1000;
public void DispAllPath(Graph graph,int[][] A,int[][] path) {
int i,j,k,s,d;
int[] apath = new int[max];
for (i=0;i<graph.thevexs.length;i++) {
for(j=0;j<graph.thevexs.length;j++) {
if (A[i][j] != INF && i!=j) {
System.out.printf("顶点%d到%d最短路径长度为：%d\t路径：",i,j,A[i][j]);
k=path[i][j];
d=0;
apath[d] = j;
while (k!= -1&& k!=i) {
d++;
apath[d] = k;
k = path[i][k];
}
d++;
apath[d] = i;
System.out.printf("%d", apath[d]);
for(s=d-1;s>=0;s--) {
System.out.printf("->%d",apath[s]);
}
System.out.println("\n");
}
}
}

}

public void Dispdispath(int[][] A,int [][] path,int n,int k) {
int i,j;
System.out.printf("\tA[%d]\t\t\t\tpath[%d]\n",k,k);
for(i=0;i<n;i++) {
for(j=0;j<n;j++) {
if (A[i][j]==INF) {
System.out.printf("%4s", "*");
} else {
System.out.printf("%4d",A[i][j]);
}
}

for(j=0;j<n;j++) {
System.out.printf("%3d",path[i][j]);
}
System.out.println("\n");
}

}

public Floyd(Graph graph) {
int[][] A = new int[max][max];
int[][] path = new int[max][max];
int i,j,k;
for(i=0;i<graph.thevexs.length;i++) {
for(j=0;j<graph.thevexs.length;j++) {
A[i][j]  = graph.edges[i][j];
if (i!=j && graph.edges[i][j]<INF) {
path[i][j] = i;
}else {
path[i][j]=-1;
}
}
}
Dispdispath(A, path, graph.thevexs.length, -1);

for(k=0;k<graph.thevexs.length;k++) {
for(i=0;i<graph.thevexs.length;i++) {
for(j=0;j<graph.thevexs.length;j++) {
if (A[i][j]>A[i][k]+A[k][j]) {
A[i][j]=A[i][k]+A[k][j];
path[i][j] = path[k][j];
}
}
}
Dispdispath(A, path,graph.thevexs.length, k);
}
DispAllPath(graph, A, path);

}

}

package floyd;

public class Test {

public static void main(String[] args) {
final int INF = 1000;
int[] vexs = {0,1,2,3,4,5};
int[][] A ={
{0,50,10,INF,INF,INF},
{INF,0,15,50,10,INF},
{20,INF,0,15,INF,INF},
{INF,20,INF,0,35,INF},
{INF,INF,INF,30,0,INF},
{INF,INF,INF,3,INF,0},

};
Graph graph = new Graph();
graph.createGraph(graph, A, vexs);
graph.printGraph(graph);
Floyd floyd = new Floyd(graph);
}

}

多源最短路径（ Floyd算法）JAVA实现

package floyd;

public class Graph {
final int max=100;
/*
* 顶点节点
*/
public class VexNode{
int adjvex;
int data;
}

VexNode[] vexNodes;
int[] thevexs; //顶点集合
int[][] edges = new int[max][max]; //边集合

/*
* 创建图
*/
public void createGraph(Graph graph,int[][] A,int[] vexs) {
thevexs=vexs;
for (int i = 0; i < vexs.length; i++) {
for (int j = 0; j < vexs.length; j++) {
graph.edges[i][j] = A[i][j];
}
}
}

/*
* 输出图
*/
public void printGraph(Graph graph) {
for (int i = 0; i < graph.thevexs.length; i++) {
for (int j = 0; j < graph.thevexs.length; j++) {
//没有路径则输出/
if (graph.edges[i][j]==1000) {
System.out.printf("%4s","/");

}else {
System.out.printf("%4d",graph.edges[i][j]);
}

}
System.out.println("\n");
}
}

}

package floyd;

public class Floyd {
final int max = 100;
final int INF = 1000;
public void DispAllPath(Graph graph,int[][] A,int[][] path) {
int i,j,k,s,d;
int[] apath = new int[max];
for (i=0;i<graph.thevexs.length;i++) {
for(j=0;j<graph.thevexs.length;j++) {
if (A[i][j] != INF && i!=j) {
System.out.printf("顶点%d到%d最短路径长度为：%d\t路径：",i,j,A[i][j]);
k=path[i][j];
d=0;
apath[d] = j;
while (k!= -1&& k!=i) {
d++;
apath[d] = k;
k = path[i][k];
}
d++;
apath[d] = i;
System.out.printf("%d", apath[d]);
for(s=d-1;s>=0;s--) {
System.out.printf("->%d",apath[s]);
}
System.out.println("\n");
}
}
}

}

public void Dispdispath(int[][] A,int [][] path,int n,int k) {
int i,j;
System.out.printf("\tA[%d]\t\t\t\tpath[%d]\n",k,k);
for(i=0;i<n;i++) {
for(j=0;j<n;j++) {
if (A[i][j]==INF) {
System.out.printf("%4s", "*");
} else {
System.out.printf("%4d",A[i][j]);
}
}

for(j=0;j<n;j++) {
System.out.printf("%3d",path[i][j]);
}
System.out.println("\n");
}

}

public Floyd(Graph graph) {
int[][] A = new int[max][max];
int[][] path = new int[max][max];
int i,j,k;
for(i=0;i<graph.thevexs.length;i++) {
for(j=0;j<graph.thevexs.length;j++) {
A[i][j]  = graph.edges[i][j];
if (i!=j && graph.edges[i][j]<INF) {
path[i][j] = i;
}else {
path[i][j]=-1;
}
}
}
Dispdispath(A, path, graph.thevexs.length, -1);

for(k=0;k<graph.thevexs.length;k++) {
for(i=0;i<graph.thevexs.length;i++) {
for(j=0;j<graph.thevexs.length;j++) {
if (A[i][j]>A[i][k]+A[k][j]) {
A[i][j]=A[i][k]+A[k][j];
path[i][j] = path[k][j];
}
}
}
Dispdispath(A, path,graph.thevexs.length, k);
}
DispAllPath(graph, A, path);

}

}

package floyd;

public class Test {

public static void main(String[] args) {
final int INF = 1000;
int[] vexs = {0,1,2,3,4,5};
int[][] A ={
{0,50,10,INF,INF,INF},
{INF,0,15,50,10,INF},
{20,INF,0,15,INF,INF},
{INF,20,INF,0,35,INF},
{INF,INF,INF,30,0,INF},
{INF,INF,INF,3,INF,0},

};
Graph graph = new Graph();
graph.createGraph(graph, A, vexs);
graph.printGraph(graph);
Floyd floyd = new Floyd(graph);
}

}