UVa 544 - Heavy Cargo

544 - Heavy Cargo

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Summary
Modified dijkstra allgorithm

Solution import java.io.PrintWriter; import java.util.ArrayList; import java.util.Collection; import java.util.Comparator; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.PriorityQueue; import java.util.Scanner;

class Main { public static void main(String[] args) throws Exception { Scanner in = new Scanner(System.in); PrintWriter out = new PrintWriter(System.out, true); int set = 0; Map cityNodeMap = new HashMap<>; while (in.hasNextInt) { set++; int n = in.nextInt;// ceties int m = in.nextInt;// roads if (n == 0 && m == 0) { out.flush; out.close; return; }			out.println("Scenario #" + set); // last city index int index = 0; List nodeList = new ArrayList; for (int i = 0; i < m; i++) { String from = in.next; String to = in.next; int weigth = in.nextInt; Node a, b;				if ((a = cityNodeMap.get(from)) == null) { a = new Node(index++, from); cityNodeMap.put(from, a); }				if ((b = cityNodeMap.get(to)) == null) { b = new Node(index++, to); cityNodeMap.put(to, b); }				Edge e1 = new Edge(a, b, weigth); Edge e2 = new Edge(b, a, weigth); a.getEdges.add(e1); b.getEdges.add(e2); }			String start = in.next; String end = in.next; Node startNode = cityNodeMap.get(start); Node endNode = cityNodeMap.get(end);

// dijkstra PriorityQueue queue = new PriorityQueue(n, new NodeComparator); Collection nl = cityNodeMap.values; for (Iterator iterator = nl.iterator; iterator.hasNext;) { Node node = (Node) iterator.next; node.setCurrentCost(0); queue.add(node); }			queue.remove(startNode); startNode.setCurrentCost(Integer.MAX_VALUE); queue.add(startNode);

while (!queue.isEmpty) { Node currentNode = queue.remove; List edges = currentNode.getEdges; for (int i = 0; i < edges.size; i++) { Edge e = edges.get(i);

Node src = e.getStart; Node dst = e.getEnd; int cost = e.getCost;

if (dst.getCurrentCost < Math.max(dst.getCurrentCost, Math.min(src.getCurrentCost, cost))) { queue.remove(dst); dst.setCurrentCost(Math.max(dst.getCurrentCost, Math.min(src.getCurrentCost, cost))); dst.setPreviousNode(src); queue.add(dst); }				}			}

int currentCost = endNode.getCurrentCost;

out.println(currentCost + " tons"); out.println(""); }

out.flush; out.close;

} }

class Edge { private Node start; private Node end; private int cost;

public Edge(Node start, Node end, int cost) { this.start = start; this.end = end; this.cost = cost; }

public Node getStart { return start; }

public void setStart(Node start) { this.start = start; }

public Node getEnd { return end; }

public void setEnd(Node end) { this.end = end; }

public int getCost { return cost; }

public void setCost(int cost) { this.cost = cost; } }

class Node { private int n;	private List edges = new ArrayList;

private int currentCost = 0; private Node previousNode; private String name;

public Node(int n, String name) { this.n = n;		this.name = name; }

private boolean solved = false; public boolean isSolved { return solved; }

public void setSolved(boolean solved) { this.solved = solved; }

@Override public String toString { return "Node [n=" + n + ", currentCost=" + currentCost + ", previousNode=" + previousNode + ", name=" + name + "]"; }

public void addEdge(Edge e) { edges.add(e); }

public List getEdges { return edges; }

public int getCurrentCost { return currentCost; }

public void setCurrentCost(int currentCost) { this.currentCost = currentCost; }

public Node getPreviousNode { return previousNode; }

public void setPreviousNode(Node previousNode) { this.previousNode = previousNode; }

public int getN { return n;	}

@Override public int hashCode { final int prime = 31; int result = 1; result = prime * result + n;		return result; }

@Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass != obj.getClass) return false; Node other = (Node) obj; if (n != other.n)			return false; return true; }

}

class NodeComparator implements Comparator {

public int compare(Node o1, Node o2) { if (o1.getCurrentCost == o2.getCurrentCost) { return 0; } else if (o1.getCurrentCost > o2.getCurrentCost) { return -1; } else if (o1.getCurrentCost < o2.getCurrentCost) { return 1; }		return 0; }

}