algorithm/Java
1
0
Fork 0
mirror of https://github.com/TheAlgorithms/Java.git synced 2025-07-12 22:56:11 +08:00
Code Issues Packages Projects Releases Wiki Activity

Update FloydWarshall.java

Browse Source
This commit is contained in:
Ayush Nagar
2018-05-06 17:16:19 +05:30
committed by GitHub
parent 35a4bd314d
commit ba22b1c6b8
1 changed files with 17 additions and 112 deletions
Download Patch File Download Diff File Expand all files Collapse all files

129
Data Structures/Graphs/FloydWarshall.java
View File

@ -1,173 +1,78 @@
import java.util.Scanner;
public class FloydWarshall
{
private int distancematrix[][];
private int numberofvertices;
private int DistanceMatrix[][];
private int numberofvertices;//number of vertices in the graph
public static final int INFINITY = 999;
public FloydWarshall(int numberofvertices)
{
distancematrix = new int[numberofvertices + 1][numberofvertices + 1];
DistanceMatrix = new int[numberofvertices + 1][numberofvertices + 1];//stores the value of distance from all the possible path form the source vertex to destination vertex
Arrays.fill(DistanceMatrix, 0);
this.numberofvertices = numberofvertices;
}
public void floydwarshall(int adjacencymatrix[][])
public void floydwarshall(int AdjacencyMatrix[][])//calculates all the distances from source to destination vertex
{
for (int source = 1; source <= numberofvertices; source++)
{
for (int destination = 1; destination <= numberofvertices; destination++)
{
distancematrix[source][destination] = adjacencymatrix[source][destination];
DistanceMatrix[source][destination] = AdjacencyMatrix[source][destination];
}
}
for (int intermediate = 1; intermediate <= numberofvertices; intermediate++)
{
for (int source = 1; source <= numberofvertices; source++)
{
for (int destination = 1; destination <= numberofvertices; destination++)
{
if (distancematrix[source][intermediate] + distancematrix[intermediate][destination]
< distancematrix[source][destination])
distancematrix[source][destination] = distancematrix[source][intermediate]
+ distancematrix[intermediate][destination];
if (DistanceMatrix[source][intermediate] + DistanceMatrix[intermediate][destination]
< DistanceMatrix[source][destination])//if the new distance calculated is less then the earlier shortest calculated distance it get replaced as new shortest distance
DistanceMatrix[source][destination] = DistanceMatrix[source][intermediate]
+ DistanceMatrix[intermediate][destination];
}
}
}
for (int source = 1; source <= numberofvertices; source++)
System.out.print("\t" + source);
System.out.println();
for (int source = 1; source <= numberofvertices; source++)
{
System.out.print(source + "\t");
for (int destination = 1; destination <= numberofvertices; destination++)
{
System.out.print(distancematrix[source][destination] + "\t");
System.out.print(DistanceMatrix[source][destination] + "\t");
}
System.out.println();
}
}
public static void main(String... arg)
{
int adjacency_matrix[][];
int Adjacency_Matrix[][];
int numberofvertices;
Scanner scan = new Scanner(System.in);
System.out.println("Enter the number of vertices");
numberofvertices = scan.nextInt();
adjacency_matrix = new int[numberofvertices + 1][numberofvertices + 1];
Adjacency_Matrix = new int[numberofvertices + 1][numberofvertices + 1];
System.out.println("Enter the Weighted Matrix for the graph");
for (int source = 1; source <= numberofvertices; source++)
{
for (int destination = 1; destination <= numberofvertices; destination++)
{
adjacency_matrix[source][destination] = scan.nextInt();
Adjacency_Matrix[source][destination] = scan.nextInt();
if (source == destination)
{
adjacency_matrix[source][destination] = 0;
Adjacency_Matrix[source][destination] = 0;
continue;
}
if (adjacency_matrix[source][destination] == 0)
if (Adjacency_Matrix[source][destination] == 0)
{
adjacency_matrix[source][destination] = INFINITY;
Adjacency_Matrix[source][destination] = INFINITY;
}
}
}
System.out.println("The Transitive Closure of the Graph");
FloydWarshall floydwarshall = new FloydWarshall(numberofvertices);
floydwarshall.floydwarshall(adjacency_matrix);
scan.close();
}
}