已经在spojtoolkit上尝试了大多数测试用例，它们都为我的输出提供了匹配的答案。
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;
import java.util.PriorityQueue;
public class Main {
static class Reader {
final private int BUFFER_SIZE = 1 << 16;
private DataInputStream din;
private byte[] buffer;
private int bufferPointer, bytesRead;
public Reader() {
din = new DataInputStream(System.in);
buffer = new byte[BUFFER_SIZE];
bufferPointer = bytesRead = 0;
}
public Reader(String file_name) throws IOException {
din = new DataInputStream(new FileInputStream(file_name));
buffer = new byte[BUFFER_SIZE];
bufferPointer = bytesRead = 0;
}
public String readLine() throws IOException {
byte[] buf = new byte[64]; // line length
int cnt = 0, c;
while ((c = read()) != -1) {
if (c == '\n') {
break;
}
buf[cnt++] = (byte) c;
}
return new String(buf, 0, cnt);
}
public int nextInt() throws IOException {
int ret = 0;
byte c = read();
while (c <= ' ') {
c = read();
}
boolean neg = (c == '-');
if (neg) {
c = read();
}
do {
ret = ret * 10 + c - '0';
} while ((c = read()) >= '0' && c <= '9');
if (neg) {
return -ret;
}
return ret;
}
private void fillBuffer() throws IOException {
bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
if (bytesRead == -1) {
buffer[0] = -1;
}
}
private byte read() throws IOException {
if (bufferPointer == bytesRead) {
fillBuffer();
}
return buffer[bufferPointer++];
}
public void close() throws IOException {
if (din == null) {
return;
}
din.close();
}
}
public static void main（String [] args）{
StringBuilder sba = new StringBuilder();
try {
Reader sc = new Reader();
int t = sc.nextInt();
while (t-- > 0) {
int n = sc.nextInt();
int numOfEdges = sc.nextInt();
int src = sc.nextInt();
int dest = sc.nextInt();
graph g = new graph(src - 1, dest - 1);
for (int i = 0; i < n; i++) {
g.addVertex(new vertex(i + 1));
}
for (int i = 0; i < numOfEdges; i++) {
int source = sc.nextInt();
int destination = sc.nextInt();
int weight = sc.nextInt();
g.addEdge(g.vertexList.get(source - 1), g.vertexList.get(destination - 1), weight);
}
int count = g.disjkstra(g.vertexList.get(g.srcCellVertexIndex), g.vertexList.get(g.destCellVertexIndex));
if (count != Integer.MAX_VALUE) {
sba.append(count).append("\n");
} else {
sba.append("NONE").append("\n");
}
}
sba.deleteCharAt(sba.length()-1);
System.out.println(sba.toString());
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
}
class graph
{
public int srcCellVertexIndex, destCellVertexIndex;
;
public ArrayList<vertex> vertexList;
public int numOfVertices;
public ArrayList<LinkedList<edge>> adjList;
public graph(int src, int dest) {
srcCellVertexIndex = src;
destCellVertexIndex = dest;
vertexList = new ArrayList<>();
adjList = new ArrayList<>();
numOfVertices = 0;
}
public void addVertex(vertex vert) {
vertexList.add(vert);
adjList.add(new LinkedList<>());
numOfVertices++;
}
public void addEdge（顶点源，顶点目标，整数重量）{
edge lp = new edge(source, destination, weight);
adjList.get(source.label-1).add(lp);
lp = new edge(destination, source, weight);
adjList.get(destination.label-1).add(lp);
}
public int disjkstra（vertex v，vertex exitCell）{
if (v == exitCell) {
return 0;
}
v.visited = true;
v.timeExhausted = 0;
PriorityQueue<edge> pq = new PriorityQueue<>(new Comparator<edge>() {
@Override
public int compare(edge t, edge t1) {
if (t.weight <= t1.weight) {
return -1;
} else {
return 1;
}
}
});
adjList.get(v.label - 1).forEach(e -> {
if(e.destination!=e.source)
pq.add(e);
});
Map<vertex, Integer> mp = new HashMap<>();
while (!pq.isEmpty()) {
edge e = pq.poll();
mp.put(e.source, 0);
vertex destAdjListHead = e.destination;
if (!adjList.get(e.destination.label - 1).isEmpty()) {
adjList.get(destAdjListHead.label - 1).forEach(p -> {
if (!mp.containsKey(p.destination)) {
pq.add(p);
}
});
}
if (e.destination.timeExhausted > (e.weight + e.source.timeExhausted)) {
e.destination.timeExhausted = (e.weight + e.source.timeExhausted);
}
}
// System.out.println("returning "+exitCell.timeExhausted);
return exitCell.timeExhausted;
}
}
顶点结构
类顶点{
public int label, timeExhausted;
public boolean visited;
public vertex(int label) {
this.label = label;
this.visited = false;
this.timeExhausted = Integer.MAX_VALUE;
}
}
边缘结构
阶级边缘{
vertex source, destination;
int weight;
public edge(vertex source, vertex destination, int weight) {
this.source = source;
this.destination = destination;
this.weight = weight;
}
}