我正在尝试修改https://github.com/lhelwerd/WebGraph/blob/master/src/it/unimi/dsi/webgraph/examples/BreadthFirst.java
只需添加深度优先搜索程序，我也将父母存储在Int2IntOpenHashMap（来自http://fastutil.di.unimi.it/docs/的自定义地图）中。现在，如果我注释掉dfs过程，它可以正常工作，即Int2IntOpenHashMap似乎实际上是导入的，因为编译器不会抱怨。但是一旦我包含了dfs主体，mvn install说＆＃34;找不到符号＆lt; ...＆gt; Int2IntOpenHashMap＆＃34;类型的父类。怎么可能导入包，但找不到变量？
编辑：我正在使用命令行专家，严格遵循这位绅士的安装说明：https://github.com/lhelwerd/WebGraph。
也就是说，我将依赖项解压缩到一个目录中，并将我从后一个GutHub页面获得的Webgraph解包到另一个目录中，然后从后者运行mvn install。我确信我的Java是1.8。
package it.unimi.dsi.webgraph.examples;
/*
* Copyright (C) 2003-2014 Paolo Boldi and Sebastiano Vigna
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*
*/
import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
import it.unimi.dsi.fastutil.ints.IntArrayFIFOQueue;
import it.unimi.dsi.fastutil.ints.IntArrayList;
import it.unimi.dsi.fastutil.ints.IntArrays;
import it.unimi.dsi.logging.ProgressLogger;
import it.unimi.dsi.webgraph.GraphClassParser;
import it.unimi.dsi.webgraph.ImmutableGraph;
import it.unimi.dsi.webgraph.LazyIntIterator;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import com.martiansoftware.jsap.FlaggedOption;
import com.martiansoftware.jsap.JSAP;
import com.martiansoftware.jsap.JSAPException;
import com.martiansoftware.jsap.JSAPResult;
import com.martiansoftware.jsap.Parameter;
import com.martiansoftware.jsap.SimpleJSAP;
import com.martiansoftware.jsap.Switch;
import com.martiansoftware.jsap.UnflaggedOption;
/** The main method of this class loads an arbitrary {@link it.unimi.dsi.webgraph.ImmutableGraph}
* and performs a breadth-first visit of the graph (optionally starting just from a given node, if provided,
* in which case it prints the eccentricity of the node, i.e., the maximum distance from the node).
*/
public class BreadthFirst {
private BreadthFirst() {}
static ImmutableGraph graph= null;
final static Int2IntOpenHashMap card= new Int2IntOpenHashMap(), parent= new Int2IntOpenHashMap();
final static StringBuilder sb= new StringBuilder();
private static int dfs( int x ) {
LazyIntIterator successors= graph.successors(x);
int y, w= 1, d= graph.outdegree(x);
for ( ;d-->0; ) {
y= successors.nextInt();
if ( parent.containsKey(y) && parent.getInt(y)==x ) {
int wy= dfs(y);
w += wy;
}
}
card.putInt(w);
return w;
}
@SuppressWarnings("unchecked")
static public void main( String arg[] ) throws IllegalArgumentException, SecurityException, IllegalAccessException, InvocationTargetException, NoSuchMethodException, JSAPException, IOException {
SimpleJSAP jsap = new SimpleJSAP( BreadthFirst.class.getName(), "Visits a graph in breadth-first fashion, possibly starting just from a given node.",
new Parameter[] {
new FlaggedOption( "graphClass", GraphClassParser.getParser(), null, JSAP.NOT_REQUIRED, 'g', "graph-class", "Forces a Java class for the source graph." ),
new FlaggedOption( "logInterval", JSAP.LONG_PARSER, Long.toString( ProgressLogger.DEFAULT_LOG_INTERVAL ), JSAP.NOT_REQUIRED, 'l', "log-interval", "The minimum time interval between activity logs in milliseconds." ),
new FlaggedOption( "start", JSAP.INTEGER_PARSER, Integer.toString( -1 ), JSAP.NOT_REQUIRED, 's', "start", "The starting node; if missing or -1, the visit will be complete." ),
new FlaggedOption( "maxDist", JSAP.INTEGER_PARSER, Integer.toString( Integer.MAX_VALUE ), JSAP.NOT_REQUIRED, 'm', "maxDist", "Maximum distance (nodes at larger distance from the root are not enqueued" ),
new Switch( "print", 'p', "print", "Print nodes as they are enqueued. If set, ordinary output is suppressed." ),
new UnflaggedOption( "basename", JSAP.STRING_PARSER, JSAP.NO_DEFAULT, JSAP.REQUIRED, JSAP.NOT_GREEDY, "The basename of the graph." ),
}
);
JSAPResult jsapResult = jsap.parse( arg );
if ( jsap.messagePrinted() ) System.exit( 1 );
final ProgressLogger pl = new ProgressLogger(), sl = new ProgressLogger();
pl.logInterval = jsapResult.getLong( "logInterval" );
final String basename = jsapResult.getString( "basename" );
if ( jsapResult.userSpecified( "graphClass" ) ) graph = (ImmutableGraph)(jsapResult.getClass( "graphClass" )).getMethod( "load", CharSequence.class, ProgressLogger.class ).invoke( null, basename, pl );
else graph = ImmutableGraph.load( basename, pl );
final int maxDist = jsapResult.getInt( "maxDist" );
final boolean print = jsapResult.getBoolean( "print" );
// We parse the starting node.
final int start = jsapResult.getInt( "start" );
final IntArrayFIFOQueue queue = new IntArrayFIFOQueue();
final int n = graph.numNodes();
final int[] dist = new int[ n ];
IntArrays.fill( dist, Integer.MAX_VALUE ); // Initially, all distances are infinity.
final int lo = start == -1 ? 0 : start;
final int hi = start == -1 ? n : start + 1;
int curr = lo, succ, ecc = 0, reachable = 0, best_start= -1, sx, SX = -1;
pl.start( "Starting visit..." );
pl.expectedUpdates = hi - lo;
pl.itemsName = "nodes";
LazyIntIterator successors;
for( int i = lo; i < hi; i++ ) {
if ( dist[ i ] == Integer.MAX_VALUE ) { // Not already visited
queue.enqueue( i );
if ( print ) System.out.println( i );
for ( sx= 0, dist[i]= 0; !queue.isEmpty(); ) {
curr = queue.dequeueInt();
successors = graph.successors( curr );
int d = graph.outdegree( curr );
while( d-- != 0 ) {
succ = successors.nextInt();
if ( dist[ succ ] == Integer.MAX_VALUE && dist[ curr ] + 1 <= maxDist ) {
++reachable; ++sx;
dist[ succ ] = dist[ curr ] + 1;
parent.put(succ,curr);
ecc = Math.max( ecc, dist[ succ ] );
queue.enqueue( succ );
if ( print ) System.out.println( succ );
}
}
}
if ( sx > SX ) {
SX= sx;
best_start= i;
}
}
pl.update();
}
pl.done();
if ( !print )
if ( start == -1 ) System.out.println( "The maximum depth of a tree in the breadth-first spanning forest is " + ecc );
else {
System.out.println( "The eccentricity of node " + start + " is " + ecc + " (" + reachable + " reachable nodes)" );
}
sl.start( "Starting DFS..." );
sl.expectedUpdates = hi - lo;
sl.itemsName = "nodes";
dfs(best_start);
sl.done();
}
}