Created
July 9, 2015 02:50
-
-
Save wuqifu/ccd5e608b1706d7c64ab to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import java.util.ArrayList; | |
| import java.util.LinkedList; | |
| import java.util.Queue; | |
| import java.util.Stack; | |
| public class Graph { | |
| public Node rootNode; | |
| public ArrayList<Node> nodes = new ArrayList<Node>(); | |
| public int[][] adjMatrix;// Edges will be represented as adjacency Matrix | |
| int size; | |
| public void setRootNode(Node n) { | |
| this.rootNode = n; | |
| } | |
| public Node getRootNode() { | |
| return this.rootNode; | |
| } | |
| public void addNode(Node n) { | |
| nodes.add(n); | |
| } | |
| // This method will be called to make connect two nodes | |
| public void connectNode(Node start, Node end) { | |
| if (adjMatrix == null) { | |
| size = nodes.size(); | |
| adjMatrix = new int[size][size]; | |
| } | |
| int startIndex = nodes.indexOf(start); | |
| int endIndex = nodes.indexOf(end); | |
| adjMatrix[startIndex][endIndex] = 1; | |
| adjMatrix[endIndex][startIndex] = 1; | |
| } | |
| private Node getUnvisitedChildNode(Node n) { | |
| int index = nodes.indexOf(n); | |
| int j = 0; | |
| while (j < size) { | |
| if (adjMatrix[index][j] == 1 && nodes.get(j).visited == false) { | |
| return nodes.get(j); | |
| } | |
| j++; | |
| } | |
| return null; | |
| } | |
| // BFS traversal of a tree is performed by the bfs() function | |
| public void bfs() { | |
| // BFS uses Queue data structure | |
| Queue q = new LinkedList(); | |
| q.add(this.rootNode); | |
| printNode(this.rootNode); | |
| rootNode.visited = true; | |
| while (!q.isEmpty()) { | |
| Node n = (Node) q.remove(); | |
| Node child = null; | |
| while ((child = getUnvisitedChildNode(n)) != null) { | |
| child.visited = true; | |
| printNode(child); | |
| q.add(child); | |
| } | |
| } | |
| // Clear visited property of nodes | |
| clearNodes(); | |
| } | |
| // DFS traversal of a tree is performed by the dfs() function | |
| public void dfs() { | |
| // DFS uses Stack data structure | |
| Stack s = new Stack(); | |
| s.push(this.rootNode); | |
| rootNode.visited = true; | |
| printNode(rootNode); | |
| while (!s.isEmpty()) { | |
| Node n = (Node) s.peek(); | |
| Node child = getUnvisitedChildNode(n); | |
| if (child != null) { | |
| child.visited = true; | |
| printNode(child); | |
| s.push(child); | |
| } else { | |
| s.pop(); | |
| } | |
| } | |
| // Clear visited property of nodes | |
| clearNodes(); | |
| } | |
| // Utility methods for clearing visited property of node | |
| private void clearNodes() { | |
| int i = 0; | |
| while (i < size) { | |
| Node n = nodes.get(i); | |
| n.visited = false; | |
| i++; | |
| } | |
| } | |
| // Utility methods for printing the node's label | |
| private void printNode(Node n) { | |
| System.out.print(n.label + " "); | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment