algorithm/Java
1
0
Fork 0
mirror of https://github.com/TheAlgorithms/Java.git synced 2025-07-24 21:14:00 +08:00
Code Issues Packages Projects Releases Wiki Activity

Formatted with Google Java Formatter

Browse Source
This commit is contained in:
github-actions
2020-10-24 10:23:28 +00:00
parent a23bac99e8
commit 5d59a2e828
219 changed files with 13758 additions and 14582 deletions
Download Patch File Download Diff File Expand all files Collapse all files

124
DataStructures/Graphs/FloydWarshall.java
View File

@ -4,70 +4,74 @@ import java.util.Arrays;
import java.util.Scanner;
public class FloydWarshall {
private int DistanceMatrix[][];
private int numberofvertices;//number of vertices in the graph
public static final int INFINITY = 999;
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];//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 FloydWarshall(int numberofvertices) {
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[][])//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];
}
}
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])
// 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.println();
}
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];
}
}
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])
// 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.println();
}
}
public static void main(String... arg) {
Scanner scan = new Scanner(System.in);
System.out.println("Enter the number of vertices");
int numberOfVertices = scan.nextInt();
int[][] adjacencyMatrix = 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++) {
adjacencyMatrix[source][destination] = scan.nextInt();
if (source == destination) {
adjacencyMatrix[source][destination] = 0;
continue;
}
if (adjacencyMatrix[source][destination] == 0) {
adjacencyMatrix[source][destination] = INFINITY;
}
}
public static void main(String... arg) {
Scanner scan = new Scanner(System.in);
System.out.println("Enter the number of vertices");
int numberOfVertices = scan.nextInt();
int[][] adjacencyMatrix = 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++) {
adjacencyMatrix[source][destination] = scan.nextInt();
if (source == destination) {
adjacencyMatrix[source][destination] = 0;
continue;
}
System.out.println("The Transitive Closure of the Graph");
FloydWarshall floydwarshall = new FloydWarshall(numberOfVertices);
floydwarshall.floydwarshall(adjacencyMatrix);
scan.close();
if (adjacencyMatrix[source][destination] == 0) {
adjacencyMatrix[source][destination] = INFINITY;
}
}
}
System.out.println("The Transitive Closure of the Graph");
FloydWarshall floydwarshall = new FloydWarshall(numberOfVertices);
floydwarshall.floydwarshall(adjacencyMatrix);
scan.close();
}
}