// Java

/******************************************
use variable graph to access Graph methods 
(e.g. graph.getVertexCount())

Goto http://www.inf.ethz.ch/~braendle/graphbench 
for Java API
******************************************/

import ch.ethz.graphbench.toolbox.*;

// import Iterator class
import java.util.Iterator;

public class ShortestEdge extends GraphAlgorithm{

  public void executeAlgorithm(){
    // make sure graph has edges at all
    if(graph.getEdgeCount() == 0){
      return;
    }

    // reset all edges states
    graph.resetStates();

    // get an iterator over all edges
    Iterator edgeIterator = graph.getEdgeIterator();

    // get the first edge and save it as the shortest so far
    Edge shortestEdge = (Edge)edgeIterator.next();
    // mark the edge as valid, to visualize that this is the shortest edge so far
    shortestEdge.setEdgeState(Edge.VALID_STATE);

    // Reference to the edge that is currently being proccessed
    Edge currentEdge;
    
    // go through all other edges
    while(edgeIterator.hasNext()){
      // get the next edge and cast it
      currentEdge = (Edge)edgeIterator.next();
      // mark it as active
      currentEdge.setEdgeState(Edge.ACTIVE_STATE);
      // test if it is shorter then the shortest one so far
      if(currentEdge.getLength() < shortestEdge.getLength()){
        // if it is shorter
        // mark the previously shortest one as processed
        shortestEdge.setEdgeState(Edge.PROCESSED_STATE);
        // save current edge as the shortest one
        shortestEdge = currentEdge;
        // mark it as valid
        currentEdge.setEdgeState(Edge.VALID_STATE);
      }else{
        // current edge has been processed
        currentEdge.setEdgeState(Edge.PROCESSED_STATE);
      }
    }
    // reset all edges states
    graph.resetStates();
    // and mark only the shortest one
    shortestEdge.setEdgeState(Edge.VALID_STATE);
  }
}