46 lines
850 B
Java
46 lines
850 B
Java
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import java.util.*;
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public class Graph {
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public Map<Integer, Set<Integer>> edges = new TreeMap<>();
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public void addNode(int u) {
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if (!edges.containsKey(u)) {
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edges.put(u, new TreeSet<Integer>());
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}
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}
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public void removeNode(int u) {
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if (!edges.containsKey(u)) {
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return;
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}
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for (int v : edges.get(u)) {
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edges.get(v).remove(u);
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}
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edges.remove(u);
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}
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public void addEdge(int u, int v) {
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addNode(u);
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addNode(v);
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edges.get(u).add(v);
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edges.get(v).add(u);
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}
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public void removeEdge(int u, int v) {
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edges.get(u).remove(v);
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edges.get(v).remove(u);
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}
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// Usage example
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public static void main(String[] args) {
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Graph g = new Graph();
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g.addEdge(0, 1);
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g.addEdge(1, 2);
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System.out.println(g.edges);
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g.removeEdge(1, 0);
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System.out.println(g.edges);
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g.removeNode(1);
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System.out.println(g.edges);
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}
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}
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