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A+ January 2017: Roads
This commit is contained in:
Xevion
799
uil/aplus-january-2017/src/Roads.java
Normal file
799
uil/aplus-january-2017/src/Roads.java
Normal file
@@ -0,0 +1,799 @@
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import java.io.File;
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import java.io.FileNotFoundException;
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import java.util.*;
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interface Intersection
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{
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void register(int intersection, Node node);
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Intersection[] vertices();
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int getVertexCount();
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List<Integer> getEdges();
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}
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/**
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* One of the two intersection variations where one of the edges faces upwards.
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*/
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class UpIntersection implements Intersection
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{
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Node edgeUp; // via Edge C
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Node edgeLeft; // via Edge A
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Node edgeRight; // via Edge E
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Intersection vertexDown; // edgeLeft.b || edgeRight.d
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Intersection vertexLeft; // edgeLeft.f || edgeUp.d
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Intersection vertexRight; // edgeRight.f || edgeUp.b
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public void registerA(Node node)
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{
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assert node != null;
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this.edgeLeft = node;
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if (vertexDown == null) vertexDown = edgeLeft.b;
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if (vertexLeft == null) vertexLeft = edgeLeft.f;
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node.a = this;
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}
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public void registerC(Node node)
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{
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assert node != null;
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this.edgeUp = node;
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if (vertexLeft == null) vertexLeft = edgeUp.d;
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if (vertexRight == null) vertexRight = edgeUp.b;
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node.c = this;
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}
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public void registerE(Node node)
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{
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assert node != null;
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this.edgeRight = node;
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if (vertexDown == null) vertexDown = edgeRight.d;
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if (vertexRight == null) vertexRight = edgeRight.f;
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node.e = this;
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}
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@Override
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public void register(int intersectionIndex, Node node)
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{
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switch (intersectionIndex % 6) {
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case 0: // Intersection A
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registerA(node);
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break;
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case 2: // Intersection C
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registerC(node);
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break;
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case 4: // Intersection E
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registerE(node);
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break;
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default:
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throw new IllegalArgumentException(
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String.format(Locale.ENGLISH, "Intersection index (%d) must be a positive even number.", intersectionIndex)
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);
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}
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}
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public Intersection[] vertices()
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{
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return new Intersection[]{vertexDown, vertexLeft, vertexRight};
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}
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@Override
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public int getVertexCount()
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{
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int i = 0;
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if (vertexRight != null) i++;
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if (vertexLeft != null) i++;
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if (vertexDown != null) i++;
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return i;
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}
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@Override
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public List<Integer> getEdges()
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{
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LinkedList<Integer> edges = new LinkedList<>();
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if (edgeLeft != null) edges.offer(edgeLeft.id);
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if (edgeRight != null) edges.offer(edgeRight.id);
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if (edgeUp != null) edges.offer(edgeUp.id);
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Collections.sort(edges);
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return edges;
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}
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@Override
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public String toString()
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{
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return String.format("UpIntersection{%d, %d, %d}", edgeUp != null ? edgeUp.id : null,
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edgeLeft != null ? edgeLeft.id : null,
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edgeRight != null ? edgeRight.id : null);
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}
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@Override
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public boolean equals(Object o)
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{
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if (this == o) return true;
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if (o == null || getClass() != o.getClass()) return false;
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UpIntersection that = (UpIntersection) o;
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return Objects.equals(edgeUp, that.edgeUp) &&
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Objects.equals(edgeLeft, that.edgeLeft) &&
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Objects.equals(edgeRight, that.edgeRight);
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}
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@Override
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public int hashCode()
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{
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return Objects.hash(edgeUp, edgeLeft, edgeRight);
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}
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}
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/**
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* One of the two intersection variations where one of the edges faces downwards.
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*/
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class DownIntersection implements Intersection
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{
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Node edgeDown; // via Edge F
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Node edgeLeft; // via Edge B
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Node edgeRight; // via Edge D
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Intersection vertexUp; // edgeLeft.b || edgeRight.e
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Intersection vertexLeft; // edgeLeft.c || edgeDown.e
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Intersection vertexRight; // edgeRight.c || edgeDown.a
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public void registerB(Node node)
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{
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assert node != null;
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this.edgeLeft = node;
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if (vertexUp == null) vertexUp = edgeLeft.a;
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if (vertexLeft == null) vertexLeft = edgeLeft.c;
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node.b = this;
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}
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public void registerD(Node node)
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{
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assert node != null;
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this.edgeRight = node;
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if (vertexUp == null) vertexUp = edgeRight.e;
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if (vertexRight == null) vertexRight = edgeRight.c;
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node.d = this;
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}
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public void registerF(Node node)
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{
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assert node != null;
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this.edgeDown = node;
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if (vertexLeft == null) vertexLeft = edgeDown.e;
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if (vertexRight == null) vertexRight = edgeDown.a;
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node.f = this;
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}
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@Override
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public void register(int intersectionIndex, Node node)
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{
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switch (intersectionIndex % 6) {
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case 1: // Intersection B
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registerB(node);
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break;
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case 3: // Intersection D
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registerD(node);
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break;
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case 5: // Intersection F
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registerF(node);
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break;
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default:
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throw new IllegalArgumentException(
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String.format(Locale.ENGLISH, "Intersection index (%d) must be a positive odd number.", intersectionIndex)
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);
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}
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}
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public Intersection[] vertices()
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{
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return new Intersection[]{vertexUp, vertexLeft, vertexRight};
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}
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@Override
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public int getVertexCount()
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{
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int i = 0;
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if (vertexRight != null) i++;
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if (vertexLeft != null) i++;
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if (vertexUp != null) i++;
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return i;
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}
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@Override
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public List<Integer> getEdges()
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{
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LinkedList<Integer> edges = new LinkedList<>();
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if (edgeLeft != null) edges.offer(edgeLeft.id);
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if (edgeRight != null) edges.offer(edgeRight.id);
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if (edgeDown != null) edges.offer(edgeDown.id);
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Collections.sort(edges);
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return edges;
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}
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@Override
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public boolean equals(Object o)
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{
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if (this == o) return true;
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if (o == null || getClass() != o.getClass()) return false;
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DownIntersection that = (DownIntersection) o;
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return Objects.equals(edgeDown, that.edgeDown) &&
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Objects.equals(edgeLeft, that.edgeLeft) &&
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Objects.equals(edgeRight, that.edgeRight);
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}
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@Override
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public int hashCode()
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{
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return Objects.hash(edgeDown, edgeLeft, edgeRight);
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}
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@Override
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public String toString()
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{
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return String.format("DownIntersection(%X, edges: [%d, %d, %d], vertices: [%X, %X, %X])",
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this.hashCode(),
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edgeDown != null ? edgeDown.id : null,
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edgeLeft != null ? edgeLeft.id : null,
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edgeRight != null ? edgeRight.id : null,
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vertexLeft != null ? vertexLeft.hashCode() : null,
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vertexRight != null ? vertexRight.hashCode() : null,
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vertexUp != null ? vertexUp.hashCode() : null);
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}
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}
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enum OffsetStyle
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{
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ODD_R,
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EVEN_R,
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ODD_Q,
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EVEN_Q
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}
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class OffsetCoordinate
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{
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public int c;
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public int r;
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private final OffsetStyle style;
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OffsetCoordinate()
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{
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this(0, 0);
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}
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OffsetCoordinate(int c, int r)
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{
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this(c, r, OffsetStyle.ODD_R);
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}
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OffsetCoordinate(int c, int r, OffsetStyle style)
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{
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this.c = c;
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this.r = r;
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this.style = style;
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}
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/**
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* @return Cube coordinate conversion of these coordinates, accounting for offset style.
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*/
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public Cube toCube()
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{
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int x, y, z;
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switch (style) {
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case ODD_R:
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x = c - (r - (r & 1)) / 2;
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z = r;
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break;
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case EVEN_R:
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x = c - (r + (r & 1)) / 2;
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z = r;
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break;
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case ODD_Q:
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x = c;
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z = r - (c - (c & 1)) / 2;
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break;
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case EVEN_Q:
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x = c;
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z = r - (c + (c & 1)) / 2;
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break;
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default:
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throw new IllegalStateException("Unexpected value: " + style);
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}
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y = -x - z;
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return new Cube(x, y, z);
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}
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}
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class Cube
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{
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||||
public int x;
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public int y;
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||||
public int z;
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Cube()
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{
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this(0, 0, 0);
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}
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||||
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||||
Cube(int x, int y, int z)
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||||
{
|
||||
this.x = x;
|
||||
this.y = y;
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||||
this.z = z;
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||||
}
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||||
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public Cube add(Cube other)
|
||||
{
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||||
return new Cube(x + other.x, y + other.y, z + other.z);
|
||||
}
|
||||
|
||||
public Cube subtract(Cube other)
|
||||
{
|
||||
return new Cube(x - other.x, y - other.y, z - other.z);
|
||||
}
|
||||
|
||||
public Cube multiply(Cube other)
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{
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return new Cube(x * other.x, y * other.y, z * other.z);
|
||||
}
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||||
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||||
public Cube divide(Cube other)
|
||||
{
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||||
return new Cube(x / other.x, y / other.y, z / other.z);
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString()
|
||||
{
|
||||
return String.format("Cube{x=%d, y=%d, z=%d}", x, y, z);
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean equals(Object o)
|
||||
{
|
||||
if (this == o) return true;
|
||||
if (o == null || getClass() != o.getClass()) return false;
|
||||
Cube cube = (Cube) o;
|
||||
return x == cube.x &&
|
||||
y == cube.y &&
|
||||
z == cube.z;
|
||||
}
|
||||
|
||||
@Override
|
||||
public int hashCode()
|
||||
{
|
||||
return Objects.hash(x, y, z);
|
||||
}
|
||||
}
|
||||
|
||||
class Node
|
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{
|
||||
private HexGraph parent;
|
||||
public int id;
|
||||
public int x;
|
||||
public int y;
|
||||
public int z;
|
||||
public Cube cube;
|
||||
|
||||
private boolean sideReady = false;
|
||||
private boolean intersectionReady = false;
|
||||
|
||||
// Sides along other Nodes
|
||||
public Node[] sides;
|
||||
public Node A;
|
||||
public Node B;
|
||||
public Node C;
|
||||
public Node D;
|
||||
public Node E;
|
||||
public Node F;
|
||||
|
||||
// Intersections touching two other Nodes
|
||||
public Intersection[] intersections;
|
||||
public UpIntersection a;
|
||||
public DownIntersection b;
|
||||
public UpIntersection c;
|
||||
public DownIntersection d;
|
||||
public UpIntersection e;
|
||||
public DownIntersection f;
|
||||
|
||||
private static final Cube[] offsets;
|
||||
public final Cube[] neighbors;
|
||||
|
||||
static {
|
||||
// A, B, C, D, E, F in that order
|
||||
offsets = new Cube[]{
|
||||
new Cube(+1, -1, 0), new Cube(+1, 0, -1), new Cube(0, +1, -1),
|
||||
new Cube(-1, +1, 0), new Cube(-1, 0, +1), new Cube(0, -1, +1)
|
||||
};
|
||||
}
|
||||
|
||||
Node(int id, int c, int r)
|
||||
{
|
||||
this(id, new OffsetCoordinate(c, r));
|
||||
|
||||
}
|
||||
|
||||
Node(int id, OffsetCoordinate coordinates)
|
||||
{
|
||||
this(id, coordinates.toCube());
|
||||
}
|
||||
|
||||
Node(int id, Cube cube)
|
||||
{
|
||||
this.id = id;
|
||||
this.x = cube.x;
|
||||
this.y = cube.y;
|
||||
this.z = cube.z;
|
||||
|
||||
this.cube = cube;
|
||||
|
||||
// Generate all Node neighbor coordinates
|
||||
int i = 0;
|
||||
neighbors = new Cube[offsets.length];
|
||||
for (Cube offset : offsets)
|
||||
neighbors[i++] = cube.add(offset);
|
||||
}
|
||||
|
||||
/**
|
||||
* Initializes neighbor references.
|
||||
*/
|
||||
public void initSides(HexGraph parent)
|
||||
{
|
||||
// Remember the parent
|
||||
this.parent = parent;
|
||||
|
||||
// Acquire all neighbors
|
||||
A = parent.getNode(neighbors[0]);
|
||||
B = parent.getNode(neighbors[1]);
|
||||
C = parent.getNode(neighbors[2]);
|
||||
D = parent.getNode(neighbors[3]);
|
||||
E = parent.getNode(neighbors[4]);
|
||||
F = parent.getNode(neighbors[5]);
|
||||
sides = new Node[]{A, B, C, D, E, F};
|
||||
|
||||
sideReady = true;
|
||||
|
||||
// Recursively initialize all neighbors
|
||||
for (Node neighbor : sides)
|
||||
if (neighbor != null && !neighbor.sideReady)
|
||||
neighbor.initSides(parent);
|
||||
}
|
||||
|
||||
public void initIntersections()
|
||||
{
|
||||
if (sideReady) {
|
||||
intersections = new Intersection[6];
|
||||
boolean[] intersectionsReady = new boolean[6];
|
||||
for (int i = 0; i < 6; i++) {
|
||||
Node[] pertinentSides = new Node[]{getSide(i), getSide(i + 1)};
|
||||
|
||||
// For each of the other two nodes in the intersection
|
||||
for (int j = 0; j < 2; j++) {
|
||||
Node possible = pertinentSides[j];
|
||||
|
||||
// Check that the neighbor is available & it has already completed it's intersection math
|
||||
if (possible != null && possible.intersectionReady) {
|
||||
Intersection inter = possible.getIntersection(i + (2 * (j + 1)));
|
||||
inter.register(i, this); // Register this node to the intersection
|
||||
intersectionsReady[i] = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
// If neighbors had no Intersection, create our own
|
||||
if (!intersectionsReady[i]) {
|
||||
Intersection intersection;
|
||||
// Alternate between Up and Down intersections on each edge
|
||||
if (i % 2 == 0)
|
||||
intersection = new UpIntersection();
|
||||
else
|
||||
intersection = new DownIntersection();
|
||||
intersection.register(i, this); // Register ourselves
|
||||
parent.intersections.add(intersection);
|
||||
|
||||
// Check the other two sides, register them to the intersection if valid sides
|
||||
for (int j = 0; j < 2; j++) {
|
||||
Node possible = pertinentSides[j];
|
||||
if (possible != null && !possible.intersectionReady) {
|
||||
int intersectionIndex = i + (2 * (j + 1));
|
||||
intersection.register(intersectionIndex, possible);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
intersections[i] = getIntersection(i);
|
||||
}
|
||||
|
||||
intersectionReady = true;
|
||||
for (Node neighbor : sides)
|
||||
if (neighbor != null && !neighbor.intersectionReady)
|
||||
neighbor.initIntersections();
|
||||
|
||||
} else {
|
||||
throw new IllegalStateException("Must call initSide() before calling initIntersection().");
|
||||
}
|
||||
}
|
||||
|
||||
private Intersection getIntersection(int i)
|
||||
{
|
||||
switch (Math.abs(i) % 6) {
|
||||
case 0:
|
||||
return a;
|
||||
case 1:
|
||||
return b;
|
||||
case 2:
|
||||
return c;
|
||||
case 3:
|
||||
return d;
|
||||
case 4:
|
||||
return e;
|
||||
case 5:
|
||||
return f;
|
||||
default:
|
||||
return intersections[i % 6];
|
||||
}
|
||||
}
|
||||
|
||||
public Node getSide(int i)
|
||||
{
|
||||
return sides[i % neighbors.length];
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean equals(Object o)
|
||||
{
|
||||
if (this == o) return true;
|
||||
if (o == null || getClass() != o.getClass()) return false;
|
||||
Node node = (Node) o;
|
||||
return id == node.id &&
|
||||
x == node.x &&
|
||||
y == node.y &&
|
||||
z == node.z;
|
||||
}
|
||||
|
||||
@Override
|
||||
public int hashCode()
|
||||
{
|
||||
return Objects.hash(x, y, z);
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString()
|
||||
{
|
||||
ArrayList<Integer> edges = new ArrayList<>();
|
||||
for (Node side : sides)
|
||||
if (side != null)
|
||||
edges.add(side.id);
|
||||
return String.format("Node{id=%d, x=%d, y=%d, z=%d, neighbors=%s}", id, x, y, z, edges);
|
||||
}
|
||||
}
|
||||
|
||||
class HexGraph
|
||||
{
|
||||
public LinkedList<Intersection> intersections;
|
||||
HashMap<Integer, Node> nodes; // HashCode -> Node
|
||||
HashMap<Integer, Node> nodesByID; // Id -> Node
|
||||
|
||||
HexGraph(String data, int[] center)
|
||||
{
|
||||
String[] rows = data.split("\n");
|
||||
nodes = new HashMap<>();
|
||||
nodesByID = new HashMap<>();
|
||||
|
||||
int r = 0, c = 0;
|
||||
for (String row : rows) {
|
||||
String[] items = row.split(" ");
|
||||
|
||||
// Fill in the row with each item
|
||||
for (String item : items) {
|
||||
// Represent holes in this hexagon-shaped graph with null
|
||||
if (!item.equals("-")) {
|
||||
Node node = new Node(Integer.parseInt(item), c - center[0], r - center[1]);
|
||||
putNode(node);
|
||||
}
|
||||
c++;
|
||||
}
|
||||
|
||||
c = 0;
|
||||
r++;
|
||||
}
|
||||
|
||||
intersections = new LinkedList<>();
|
||||
|
||||
Node centerNode = getNode(0, 0, 0);
|
||||
centerNode.initSides(this);
|
||||
centerNode.initIntersections();
|
||||
}
|
||||
|
||||
/**
|
||||
* @param x Node X coordinate
|
||||
* @param y Node Y coordinate
|
||||
* @param z Node Z coordinate
|
||||
* @return The Node with the coordinates placed into the HashMap
|
||||
*/
|
||||
public Node getNode(int x, int y, int z)
|
||||
{
|
||||
return nodes.get(Objects.hash(x, y, z));
|
||||
}
|
||||
|
||||
/**
|
||||
* @param node The node to put into the HashMap
|
||||
*/
|
||||
public void putNode(Node node)
|
||||
{
|
||||
nodes.put(node.hashCode(), node);
|
||||
nodesByID.put(node.id, node);
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString()
|
||||
{
|
||||
return String.format(Locale.ENGLISH, "%d Nodes", nodes.size());
|
||||
}
|
||||
|
||||
public Node getNode(Cube pos)
|
||||
{
|
||||
return getNode(pos.x, pos.y, pos.z);
|
||||
}
|
||||
|
||||
public Intersection findIntersection(int a, int b, int c)
|
||||
{
|
||||
Set<Intersection> potentialA = new HashSet<>(Arrays.asList(nodesByID.get(a).intersections));
|
||||
Set<Intersection> potentialB = new HashSet<>(Arrays.asList(nodesByID.get(b).intersections));
|
||||
Set<Intersection> potentialC = new HashSet<>(Arrays.asList(nodesByID.get(c).intersections));
|
||||
|
||||
potentialA.retainAll(potentialB);
|
||||
potentialA.retainAll(potentialC);
|
||||
|
||||
return (Intersection) potentialA.toArray()[0];
|
||||
}
|
||||
}
|
||||
|
||||
class Vertex implements Comparable<Vertex> {
|
||||
int id; // Unique Hashcode ID
|
||||
LinkedList<Vertex> adjacent; // All vertices this vertex touches
|
||||
int distance = Integer.MAX_VALUE; // How far this node is from the source vertex (MAX_VALUE = Infinite)
|
||||
boolean seen = false; // Whether or not the Node has been seen in the queue
|
||||
List<Integer> parentIDs; // IDs of the corresponding Node edges
|
||||
public Vertex touched; // The vertex this vertex was path'd by (LinkedList)
|
||||
|
||||
Vertex(Intersection truth) {
|
||||
this.id = truth.hashCode();
|
||||
this.parentIDs = truth.getEdges();
|
||||
this.adjacent = new LinkedList<>();
|
||||
}
|
||||
|
||||
@Override
|
||||
public int compareTo(Vertex o)
|
||||
{
|
||||
return this.distance - o.distance;
|
||||
}
|
||||
|
||||
public void addAdjacent(Vertex vertex)
|
||||
{
|
||||
adjacent.offer(vertex);
|
||||
}
|
||||
|
||||
public Stack<Vertex> getTouchStack() {
|
||||
Stack<Vertex> stack = new Stack<>();
|
||||
Vertex current = this;
|
||||
while (current.touched != null) {
|
||||
stack.add(current);
|
||||
current = current.touched;
|
||||
}
|
||||
return stack;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
return String.format("Vertex(%X, %b, distance: %d, vertices: %s, edges: %s, prev: %X)",
|
||||
id ,
|
||||
seen,
|
||||
distance,
|
||||
Arrays.toString(adjacent.stream().map(vertex -> String.format("%X", vertex.id)).toArray()),
|
||||
parentIDs,
|
||||
touched != null ? touched.id : null);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Manages a Dijkstra's Algorithm graph
|
||||
*/
|
||||
class Dijkstra
|
||||
{
|
||||
PriorityQueue<Vertex> queue;
|
||||
HashMap<Intersection, Vertex> map;
|
||||
Dijkstra(HexGraph hexGraph) {
|
||||
queue = new PriorityQueue<>();
|
||||
map = new HashMap<>();
|
||||
|
||||
// Create all Vertex objects
|
||||
for (Intersection intersection : hexGraph.intersections)
|
||||
map.put(intersection, new Vertex(intersection));
|
||||
|
||||
// Add all edges to Vertex objects
|
||||
for (Map.Entry<Intersection, Vertex> pair : map.entrySet()) {
|
||||
Vertex vertex = pair.getValue();
|
||||
for (Intersection neighbor : pair.getKey().vertices())
|
||||
if (neighbor != null) {
|
||||
vertex.addAdjacent(map.get(neighbor));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
public void generate(Intersection source) {
|
||||
generate(source, null);
|
||||
}
|
||||
|
||||
public void generate(Intersection source, Intersection destination) {
|
||||
Vertex starter = map.get(source);
|
||||
starter.distance = 0;
|
||||
|
||||
Vertex end = map.get(destination);
|
||||
queue.offer(starter);
|
||||
|
||||
while (!queue.isEmpty()) {
|
||||
Vertex extracted = queue.poll();
|
||||
|
||||
// Only start on unseen vertexes
|
||||
if (!extracted.seen) {
|
||||
extracted.seen = true;
|
||||
|
||||
if (end == extracted)
|
||||
return;
|
||||
|
||||
// Iterate along all unseen adjacents
|
||||
for (Vertex adjacent : extracted.adjacent) {
|
||||
if (!adjacent.seen) {
|
||||
int newKey = extracted.distance + 1;
|
||||
|
||||
if (newKey < adjacent.distance) {
|
||||
adjacent.distance = newKey;
|
||||
adjacent.touched = extracted;
|
||||
queue.offer(adjacent);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
public class Roads
|
||||
{
|
||||
// Simple input graph representing
|
||||
public static final String data = "- 1 2 3 -\n4 5 6 7\n8 9 10 11 12\n13 14 15 16\n- 17 18 19 -";
|
||||
public static final int[] center = new int[]{2, 2};
|
||||
|
||||
public static void main(String[] args) throws FileNotFoundException
|
||||
{
|
||||
HexGraph graph = new HexGraph(data, center);
|
||||
Scanner scanner = new Scanner(new File("roads.dat"));
|
||||
int inputs = scanner.nextInt();
|
||||
|
||||
for (int i = 0; i < inputs; i++) {
|
||||
Dijkstra dijkstra = new Dijkstra(graph);
|
||||
Intersection source = graph.findIntersection(scanner.nextInt(), scanner.nextInt(), scanner.nextInt());
|
||||
Intersection destination = graph.findIntersection(scanner.nextInt(), scanner.nextInt(), scanner.nextInt());
|
||||
dijkstra.generate(source, destination);
|
||||
|
||||
System.out.println(dijkstra.map.get(destination).distance);
|
||||
}
|
||||
}
|
||||
|
||||
public static void debugPrint(HexGraph graph) {
|
||||
// Print every node, it's intersections, and those intersection's vertices.
|
||||
for (Node node : graph.nodes.values()) {
|
||||
System.out.printf("%s\n", node);
|
||||
for (Intersection intersection : node.intersections)
|
||||
if (intersection != null) {
|
||||
System.out.println("\t" + intersection);
|
||||
for (Intersection vertex : intersection.vertices())
|
||||
System.out.println("\t\t" + vertex);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user