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Add tests, fix removeEdge bug in MatrixGraphs (#5968)

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This commit is contained in:
Hardik Pawar
2024-10-26 23:30:02 +05:30
committed by GitHub
parent a8b8420716
commit cfa35a4fd9
3 changed files with 155 additions and 14 deletions
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28
src/main/java/com/thealgorithms/datastructures/graphs/MatrixGraphs.java
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@ -102,7 +102,7 @@ class AdjacencyMatrixGraph {
/**
* Updates the number of edges in the graph
*
* @param newNumberOfEdges
* @param newNumberOfEdges the new number of edges
*
*/
private void setNumberOfEdges(int newNumberOfEdges) {
@ -202,7 +202,7 @@ class AdjacencyMatrixGraph {
* exists and is removed
*/
public boolean removeEdge(int from, int to) {
if (!this.vertexDoesExist(from) || !this.vertexDoesExist(to)) {
if (this.vertexDoesExist(from) && this.vertexDoesExist(to)) {
if (this.adjacencyOfEdgeDoesExist(from, to)) {
this.adjacency()[from][to] = AdjacencyMatrixGraph.EDGE_NONE;
this.adjacency()[to][from] = AdjacencyMatrixGraph.EDGE_NONE;
@ -223,14 +223,14 @@ class AdjacencyMatrixGraph {
public List<Integer> depthFirstOrder(int startVertex) {
// If the startVertex is invalid, return an empty list
if (startVertex >= vertexCount || startVertex < 0) {
return new ArrayList<Integer>();
return new ArrayList<>();
}
// Create an array to track the visited vertices
boolean[] visited = new boolean[vertexCount];
// Create a list to keep track of the order of our traversal
ArrayList<Integer> orderList = new ArrayList<Integer>();
ArrayList<Integer> orderList = new ArrayList<>();
// Perform our DFS algorithm
depthFirstOrder(startVertex, visited, orderList);
@ -278,18 +278,18 @@ class AdjacencyMatrixGraph {
public List<Integer> breadthFirstOrder(int startVertex) {
// If the specified startVertex is invalid, return an empty list
if (startVertex >= vertexCount || startVertex < 0) {
return new ArrayList<Integer>();
return new ArrayList<>();
}
// Create an array to keep track of the visited vertices
boolean[] visited = new boolean[vertexCount];
// Create a list to keep track of the ordered vertices
ArrayList<Integer> orderList = new ArrayList<Integer>();
ArrayList<Integer> orderList = new ArrayList<>();
// Create a queue for our BFS algorithm and add the startVertex
// to the queue
Queue<Integer> queue = new LinkedList<Integer>();
Queue<Integer> queue = new LinkedList<>();
queue.add(startVertex);
// Continue until the queue is empty
@ -327,19 +327,19 @@ class AdjacencyMatrixGraph {
* @return returns a string describing this graph
*/
public String toString() {
String s = " ";
StringBuilder s = new StringBuilder(" ");
for (int i = 0; i < this.numberOfVertices(); i++) {
s = s + i + " ";
s.append(i).append(" ");
}
s = s + " \n";
s.append(" \n");
for (int i = 0; i < this.numberOfVertices(); i++) {
s = s + i + " : ";
s.append(i).append(" : ");
for (int j = 0; j < this.numberOfVertices(); j++) {
s = s + this.adjMatrix[i][j] + " ";
s.append(this.adjMatrix[i][j]).append(" ");
}
s = s + "\n";
s.append("\n");
}
return s;
return s.toString();
}
}