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ksundongksundong
authoredSep 2, 2020
Merge pull request #48 from Data-Structure-Study/yoonexample
크루스칼 알고리즘 구현(끝)
2 parents 876f64a + dcfabc5 commit 53192e2

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‎yoonexample/src/main/java/graph/ListWeightGraph.java

+230
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@@ -0,0 +1,230 @@
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package graph;
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import java.util.Comparator;
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import java.util.StringJoiner;
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import list.DummyDoublyLinkedList;
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import list.List;
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import priorityqueue.HeapPriorityQueue;
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import priorityqueue.PriorityQueue;
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import queue.LinkedListQueue;
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import queue.Queue;
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import stack.ListStack;
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import stack.Stack;
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public class ListWeightGraph implements WeightedGraph {
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private final List<Enum<?>>[] vertices;
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private final PriorityQueue<WeightEdge> edgePriorityQueue;
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public ListWeightGraph(int vertexCount, Class<? extends Enum<?>> clazz) {
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edgePriorityQueue = new HeapPriorityQueue<>(Comparator.comparingInt(o -> o.weight));
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Enum<?>[] enumConstants = clazz.getEnumConstants();
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int min = Math.min(vertexCount, enumConstants.length);
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this.vertices = new List[min];
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for (int i = 0; i < min; i++) {
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this.vertices[i] = new DummyDoublyLinkedList<>();
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this.vertices[i].insert(enumConstants[i]);
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}
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}
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@Override
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public void addEdge(Enum<?> fromV, Enum<?> toV, int weight) {
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WeightEdge edge = new WeightEdge(weight, fromV, toV);
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vertices[fromV.ordinal()].insert(toV);
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vertices[toV.ordinal()].insert(fromV);
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edgePriorityQueue.enqueue(edge);
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}
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@Override
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public String showGraphEdgeWeightInfo() {
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List<WeightEdge> weightEdgeList = new DummyDoublyLinkedList<>();
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StringBuilder sb = new StringBuilder();
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while (!this.edgePriorityQueue.isEmpty()) {
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WeightEdge edge = this.edgePriorityQueue.dequeue();
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weightEdgeList.insert(edge);
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sb.append(edge.showEdgeInfo()).append("\n");
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}
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for (int i = 0; i < weightEdgeList.size(); i++) {
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this.edgePriorityQueue.enqueue(weightEdgeList.get(i));
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}
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return sb.toString();
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}
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@Override
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public void convertToMST() {
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int vertexCount = this.vertices.length;
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int edgeCount = this.edgePriorityQueue.size() + 1;
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List<WeightEdge> edges = new DummyDoublyLinkedList<>();
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// MST가 될 때까지 while문을 반복
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while (edgeCount != vertexCount) {
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WeightEdge edge = this.edgePriorityQueue.dequeue();
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removeEdge(edge.fromVertex, edge.toVertex); // 그래프에서 제거해본다.
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edgeCount--;
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if (!isConnectedWith(edge.fromVertex, edge.toVertex)) { // 연결되어 있지 않으면 복구
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recoverEdge(edge);
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edges.insert(edge);
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edgeCount++;
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}
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}
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// 간선 정보 복원
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for (int i = 0; i < edges.size(); i++) {
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this.edgePriorityQueue.enqueue(edges.get(i));
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}
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}
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private boolean isConnectedWith(Enum<?> fromVertex, Enum<?> toVertex) {
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boolean[] visited = new boolean[vertices.length];
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Stack<Enum<?>> vertexStack = new ListStack<>();
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vertexStack.push(fromVertex);
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while (!vertexStack.isEmpty()) {
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Enum<?> visitV = vertexStack.pop();
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if (visitVertex(visited, visitV)) {
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if (visitV.equals(toVertex)) {
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return true;
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}
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}
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List<Enum<?>> vertexList = vertices[visitV.ordinal()];
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for (int i = 0; i < vertexList.size(); i++) {
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Enum<?> vertex = vertexList.get(i);
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if (!visited[vertex.ordinal()]) {
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vertexStack.push(vertex);
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}
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}
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}
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return false;
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}
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private void recoverEdge(WeightEdge edge) {
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vertices[edge.fromVertex.ordinal()].insert(edge.toVertex);
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vertices[edge.toVertex.ordinal()].insert(edge.fromVertex);
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}
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private void removeEdge(Enum<?> fromVertex, Enum<?> toVertex) {
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removeVertexFromLink(fromVertex, toVertex);
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removeVertexFromLink(toVertex, fromVertex);
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}
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private void removeVertexFromLink(Enum<?> vertexA, Enum<?> vertexB) {
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List<Enum<?>> vertexLinkInfo = this.vertices[vertexA.ordinal()];
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for (int i = 0; i < vertexLinkInfo.size(); i++) {
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if (vertexLinkInfo.get(i).equals(vertexB)) {
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vertexLinkInfo.remove(i);
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return;
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}
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}
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throw new IllegalArgumentException("해당 정점들은 연결되어있지 않습니다.");
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}
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@Override
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public void addEdge(Enum<?> fromV, Enum<?> toV) {
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throw new UnsupportedOperationException("이 메소드는 지원하지 않습니다.");
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}
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@Override
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public String showGraphEdgeInfo() {
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StringBuilder sb = new StringBuilder();
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for (List<Enum<?>> vertex : vertices) {
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if (vertex.size() > 1) {
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for (int i = 0; i < vertex.size(); i++) {
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sb.append(vertex.get(i));
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if (i == 0) {
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sb.append(": ");
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} else if (i < vertex.size() - 1) {
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sb.append(" ");
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}
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}
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sb.append("\n");
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}
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}
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return sb.toString();
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}
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@Override
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public String depthFirstSearch(Enum<?> startV) {
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boolean[] visited = new boolean[vertices.length];
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StringJoiner sj = new StringJoiner(" ");
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Stack<Enum<?>> vertexStack = new ListStack<>();
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vertexStack.push(startV);
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while (!vertexStack.isEmpty()) {
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Enum<?> visitV = vertexStack.pop();
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if (visitVertex(visited, visitV)) {
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sj.add(visitV.toString());
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}
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List<Enum<?>> vertexList = vertices[visitV.ordinal()];
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for (int i = 0; i < vertexList.size(); i++) {
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Enum<?> vertex = vertexList.get(i);
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if (!visited[vertex.ordinal()]) {
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vertexStack.push(vertex);
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}
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}
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}
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return sj.toString();
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}
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@Override
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public String breadthFirstSearch(Enum<?> startV) {
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boolean[] visited = new boolean[vertices.length];
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StringJoiner sj = new StringJoiner(" ");
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Queue<Enum<?>> vertexQueue = new LinkedListQueue<>();
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vertexQueue.enqueue(startV);
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while (!vertexQueue.isEmpty()) {
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Enum<?> visitV = vertexQueue.dequeue();
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if (visitVertex(visited, visitV)) {
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sj.add(visitV.toString());
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}
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List<Enum<?>> vertexList = vertices[visitV.ordinal()];
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for (int i = 0; i < vertexList.size(); i++) {
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Enum<?> vertex = vertexList.get(i);
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if (!visited[vertex.ordinal()]) {
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vertexQueue.enqueue(vertex);
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}
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}
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}
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return sj.toString();
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}
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private boolean visitVertex(boolean[] visited, Enum<?> vertex) {
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if (visited[vertex.ordinal()]) {
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return false;
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}
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visited[vertex.ordinal()] = true;
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return true;
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}
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private static class WeightEdge {
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private final int weight;
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private final Enum<?> fromVertex;
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private final Enum<?> toVertex;
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public WeightEdge(int weight, Enum<?> fromVertex, Enum<?> toVertex) {
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this.weight = weight;
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this.fromVertex = fromVertex;
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this.toVertex = toVertex;
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}
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private String showEdgeInfo() {
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return "(" + fromVertex.toString() + "-" + toVertex.toString() + "), " + "w: " + weight;
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}
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}
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}

‎yoonexample/src/main/java/graph/WeightedGraph.java

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package graph;
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/**
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* 가중치 그래프의 인터페이스
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*
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* @author dion
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*/
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public interface WeightedGraph extends Graph {
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/**
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* 매개변수 fromV와 toV로 전달된 정점을 연결하는 간선에 가중치를 부여하여 그래프에 추가합니다.
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*
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* @param fromV 시작하는 정점
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* @param toV 도달하는 정점
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* @param weight 간선의 가중치
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*/
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void addEdge(Enum<?> fromV, Enum<?> toV, int weight);
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/**
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* 그래프의 간선정보 및 가중치를 반환합니다.
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*
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* @return 그래프의 간선정보 및 가중치
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*/
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String showGraphEdgeWeightInfo();
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/**
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* 크루스칼 알고리즘을 이용해 최소신장 트리로 변환합니다.
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*/
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void convertToMST();
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}

‎yoonexample/src/main/java/heap/ArrayUsefulHeap.java

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@@ -64,6 +64,11 @@ public E delete() {
6464
return retData;
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}
6666

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@Override
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public int size() {
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return this.numOfData;
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}
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/**
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* 부모 노드의 인덱스 반환 요청
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*

‎yoonexample/src/main/java/heap/UsefulHeap.java

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@@ -27,4 +27,11 @@ public interface UsefulHeap<E> {
2727
* @return 힙에 저장되어 있던 최우선순위 데이터
2828
*/
2929
E delete();
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/**
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* 힙에 저장되어 있는 데이터의 수를 반환합니다.
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*
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* @return 힙에 저장되어 있는 데이터의 수
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*/
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int size();
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}

‎yoonexample/src/main/java/priorityqueue/HeapPriorityQueue.java

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@@ -30,4 +30,9 @@ public E dequeue() {
3030
}
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return this.heap.delete();
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}
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@Override
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public int size() {
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return this.heap.size();
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}
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}

‎yoonexample/src/main/java/priorityqueue/PriorityQueue.java

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@@ -27,4 +27,11 @@ public interface PriorityQueue<E> {
2727
* @return 우선순위가 가장 높은 데이터
2828
*/
2929
E dequeue();
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/**
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* 우선순위 큐에 저장되어 있는 데이터의 수를 반환합니다.
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*
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* @return 우선순위 큐에 저장되어 있는 데이터의 수
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*/
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int size();
3037
}

‎yoonexample/src/test/java/graph/GraphTest.java

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@@ -20,7 +20,7 @@ void setUp() {
2020
}
2121

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@Test
23-
void 방향_그래프_정점_연결_테스트() {
23+
void 무방향_그래프_정점_연결_테스트() {
2424
graph.addEdge(Point.A, Point.B);
2525
assertThat(graph.showGraphEdgeInfo()).isEqualTo("A: B\nB: A\n");
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‎yoonexample/src/test/java/graph/WeightedGraphTest.java

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package graph;
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import static org.assertj.core.api.Assertions.assertThat;
4+
import static org.assertj.core.api.Assertions.assertThatThrownBy;
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import org.junit.jupiter.api.BeforeEach;
7+
import org.junit.jupiter.api.Test;
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9+
class WeightedGraphTest {
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WeightedGraph graph;
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@BeforeEach
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void setUp() {
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this.graph = new ListWeightGraph(6, Point.class);
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}
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@Test
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void 가중치_그래프_초기화_테스트() {
20+
assertThat(this.graph).isNotNull();
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}
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23+
@Test
24+
void 가중치_없이_생성하면_UnsupportedOperationException_발생_테스트() {
25+
assertThatThrownBy(() -> graph.addEdge(Point.A, Point.B))
26+
.isInstanceOf(UnsupportedOperationException.class);
27+
}
28+
29+
@Test
30+
void 가중치_그래프_정점_연결_테스트() {
31+
graph.addEdge(Point.A, Point.B, 9);
32+
assertThat(graph.showGraphEdgeInfo()).isEqualTo("A: B\nB: A\n");
33+
assertThat(graph.showGraphEdgeWeightInfo()).isEqualTo("(A-B), w: 9\n");
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35+
graph.addEdge(Point.B, Point.C, 2);
36+
assertThat(graph.showGraphEdgeInfo()).isEqualTo("A: B\nB: A C\nC: B\n");
37+
assertThat(graph.showGraphEdgeWeightInfo()).isEqualTo("(A-B), w: 9\n(B-C), w: 2\n");
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39+
graph.addEdge(Point.A, Point.C, 12);
40+
assertThat(graph.showGraphEdgeInfo()).isEqualTo("A: B C\nB: A C\nC: B A\n");
41+
assertThat(graph.showGraphEdgeWeightInfo())
42+
.isEqualTo("(A-C), w: 12\n(A-B), w: 9\n(B-C), w: 2\n");
43+
44+
graph.addEdge(Point.A, Point.D, 8);
45+
assertThat(graph.showGraphEdgeInfo()).isEqualTo("A: B C D\nB: A C\nC: B A\nD: A\n");
46+
assertThat(graph.showGraphEdgeWeightInfo())
47+
.isEqualTo("(A-C), w: 12\n(A-B), w: 9\n(A-D), w: 8\n(B-C), w: 2\n");
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49+
graph.addEdge(Point.D, Point.C, 6);
50+
assertThat(graph.showGraphEdgeInfo()).isEqualTo("A: B C D\nB: A C\nC: B A D\nD: A C\n");
51+
assertThat(graph.showGraphEdgeWeightInfo())
52+
.isEqualTo("(A-C), w: 12\n(A-B), w: 9\n(A-D), w: 8\n(D-C), w: 6\n(B-C), w: 2\n");
53+
54+
graph.addEdge(Point.A, Point.F, 11);
55+
assertThat(graph.showGraphEdgeInfo()).isEqualTo("A: B C D F\nB: A C\nC: B A D\nD: A C\nF: A\n");
56+
assertThat(graph.showGraphEdgeWeightInfo()).isEqualTo(
57+
"(A-C), w: 12\n(A-F), w: 11\n(A-B), w: 9\n(A-D), w: 8\n(D-C), w: 6\n(B-C), w: 2\n");
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59+
graph.addEdge(Point.F, Point.D, 4);
60+
assertThat(graph.showGraphEdgeInfo())
61+
.isEqualTo("A: B C D F\nB: A C\nC: B A D\nD: A C F\nF: A D\n");
62+
assertThat(graph.showGraphEdgeWeightInfo()).isEqualTo(
63+
"(A-C), w: 12\n(A-F), w: 11\n(A-B), w: 9\n(A-D), w: 8\n(D-C), w: 6\n(F-D), w: 4\n(B-C), w: 2\n");
64+
65+
graph.addEdge(Point.D, Point.E, 3);
66+
assertThat(graph.showGraphEdgeInfo())
67+
.isEqualTo("A: B C D F\nB: A C\nC: B A D\nD: A C F E\nE: D\nF: A D\n");
68+
assertThat(graph.showGraphEdgeWeightInfo()).isEqualTo(
69+
"(A-C), w: 12\n(A-F), w: 11\n(A-B), w: 9\n(A-D), w: 8\n(D-C), w: 6\n(F-D), w: 4\n(D-E), w: 3\n(B-C), w: 2\n");
70+
71+
graph.addEdge(Point.E, Point.C, 7);
72+
assertThat(graph.showGraphEdgeInfo())
73+
.isEqualTo("A: B C D F\nB: A C\nC: B A D E\nD: A C F E\nE: D C\nF: A D\n");
74+
assertThat(graph.showGraphEdgeWeightInfo()).isEqualTo(
75+
"(A-C), w: 12\n(A-F), w: 11\n(A-B), w: 9\n(A-D), w: 8\n(E-C), w: 7\n(D-C), w: 6\n(F-D), w: 4\n(D-E), w: 3\n(B-C), w: 2\n");
76+
77+
graph.addEdge(Point.F, Point.E, 13);
78+
assertThat(graph.showGraphEdgeInfo())
79+
.isEqualTo("A: B C D F\nB: A C\nC: B A D E\nD: A C F E\nE: D C F\nF: A D E\n");
80+
assertThat(graph.showGraphEdgeWeightInfo()).isEqualTo(
81+
"(F-E), w: 13\n(A-C), w: 12\n(A-F), w: 11\n(A-B), w: 9\n(A-D), w: 8\n(E-C), w: 7\n(D-C), w: 6\n(F-D), w: 4\n(D-E), w: 3\n(B-C), w: 2\n");
82+
}
83+
84+
@Test
85+
void 가중치_그래프_MST변환_테스트() {
86+
graph.addEdge(Point.A, Point.B, 9);
87+
graph.addEdge(Point.B, Point.C, 2);
88+
graph.addEdge(Point.A, Point.C, 12);
89+
graph.addEdge(Point.A, Point.D, 8);
90+
graph.addEdge(Point.D, Point.C, 6);
91+
graph.addEdge(Point.A, Point.F, 11);
92+
graph.addEdge(Point.F, Point.D, 4);
93+
graph.addEdge(Point.D, Point.E, 3);
94+
graph.addEdge(Point.E, Point.C, 7);
95+
graph.addEdge(Point.F, Point.E, 13);
96+
97+
graph.convertToMST();
98+
assertThat(graph.showGraphEdgeInfo()).isEqualTo("A: D\nB: C\nC: B D\nD: C F E A\nE: D\nF: D\n");
99+
assertThat(graph.showGraphEdgeWeightInfo())
100+
.isEqualTo("(A-D), w: 8\n(D-C), w: 6\n(F-D), w: 4\n(D-E), w: 3\n(B-C), w: 2\n");
101+
}
102+
103+
private enum Point {
104+
A, B, C, D, E, F, G, H, I, J
105+
}
106+
}

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