結果
| 問題 | No.1565 Union |
| コンテスト | |
| ユーザー |
 NASU41
|
| 提出日時 | 2021-07-09 21:17:41 |
| 言語 | Java (openjdk 23) |
| 結果 |
AC
|
| 実行時間 | 861 ms / 2,000 ms |
| コード長 | 17,536 bytes |
| 記録 | |
| コンパイル時間 | 3,724 ms |
| コンパイル使用メモリ | 105,416 KB |
| 実行使用メモリ | 87,840 KB |
| 最終ジャッジ日時 | 2025-01-02 07:19:08 |
| 合計ジャッジ時間 | 17,582 ms |
|
ジャッジサーバーID （参考情報） |
judge3 / judge4 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 27 |
ソースコード
import java.util.*;
public class Main {
public static void main(String[] args) throws Exception{
final ContestScanner sc = new ContestScanner();
final ContestPrinter pr = new ContestPrinter();
final int N = sc.nextInt(), M = sc.nextInt();
UndirectedGraph graph = new UndirectedGraph(N);
for(int m=0; m<M; m++){
graph.addEdge(sc.nextInt()-1, sc.nextInt()-1);
}
long distance = graph.dijkstra(0)[N-1];
if(distance > M+100) pr.println(-1);
else pr.println(distance);
pr.close();
}
}
class UndirectedGraph{
private static long INF = 1L << 60;
class Edge implements Comparable<Edge>{
int u,v;
long length;
public Edge(int u, int v, long l){
this.u = Math.min(u, v);
this.v = Math.max(u, v);
this.length = l;
}
public long getLength(){return length;}
public int getLeftVertex(){return u;}
public int getRightVertex(){return v;}
public int getOtherVertex(int x){
return u+v-x;
}
public String toString(){
return String.format("[%d<->%d, %d]", u, v, length);
}
public int compareTo(Edge o){
return java.util.Comparator.comparingLong(Edge::getLength)
.thenComparingInt(Edge::getLeftVertex)
.thenComparingInt(Edge::getRightVertex)
.compare(this, o);
}
}
int V, E;
java.util.List<Edge>[] edge;
java.util.ArrayList<Edge> allEdge;
public UndirectedGraph(int V){
this.V = V;
this.E = 0;
allEdge = new java.util.ArrayList<>();
edge = new java.util.ArrayList[V];
for(int v=0; v<V; v++) edge[v] = new java.util.ArrayList<>();
}
public void addEdge(int u, int v, long length){
E++;
Edge e = new Edge(u, v, length);
allEdge.add(e);
edge[u].add(e);
edge[v].add(e);
}
public void addEdge(int u, int v){
addEdge(u, v, 1L);
}
public java.util.List<Edge> getEdges(int v){return edge[v];}
public java.util.List<Edge> getAllEdges(){return allEdge;}
public long[] dijkstra(int start){
long[] ans = new long[V];
java.util.Arrays.fill(ans, INF);
java.util.PriorityQueue<Pair<Long,Integer>> queue = new java.util.PriorityQueue<>();
queue.add(new Pair<>(0L, start));
while(!queue.isEmpty()){
Pair<Long,Integer> top = queue.poll();
long d = top.getFirst();
int v = top.getSecond();
if(d > ans[v]) continue;
ans[v] = d;
for(Edge e: edge[v]){
if(d + e.getLength() < ans[e.getOtherVertex(v)]){
queue.add(new Pair<>(d + e.getLength(), e.getOtherVertex(v)));
}
}
}
return ans;
}
public long[] bellmanford(int start) throws Exception{
long[] distance = new long[V];
java.util.Arrays.fill(distance, INF);
distance[start] = 0;
for(int i=0; i<V; i++){
for(Edge e: allEdge){
int u = e.getLeftVertex(), v = e.getRightVertex();
long l = e.getLength();
if(distance[v] > distance[u] + l) distance[v] = distance[u] + l;
}
}
for(Edge e: allEdge){
int u = e.getLeftVertex(), v = e.getRightVertex();
long l = e.getLength();
if(distance[v] > distance[u] + l) throw new Exception("Bellman-Ford algorithm: negative-weight cycle found");
}
return distance;
}
public long[][] warshallfloyd(){
long[][] ans = new long[V][V];
for(int i=0; i<V; i++)for(int j=0; j<V; j++){
ans[i][j] = INF;
}
for(Edge e: allEdge){
ans[e.getLeftVertex()][e.getRightVertex()] = e.getLength();
ans[e.getRightVertex()][e.getLeftVertex()] = e.getLength();
}
for(int k=0; k<V; k++)for(int i=0; i<V; i++)for(int j=0; j<V; j++){
ans[i][j] = Math.min(ans[i][j], ans[i][k]+ans[k][j]);
}
return ans;
}
public long[] bfs01(int start){
long[] ans = new long[V];
java.util.Arrays.fill(ans, INF);
ans[start] = 0;
java.util.LinkedList<Integer> queue = new java.util.LinkedList<>();
queue.add(start);
while(!queue.isEmpty()){
int v = queue.pollFirst();
for(Edge e: getEdges(v)) if(ans[e.getOtherVertex(v)] > ans[v] + e.getLength()){
ans[e.getOtherVertex(v)] = ans[v] + e.getLength();
if(e.getLength() > 0) queue.addLast(e.getOtherVertex(v));
else queue.addFirst(e.getOtherVertex(v));
}
}
return ans;
}
public UndirectedGraph kruskal() throws Exception{
UndirectedGraph ans = new UndirectedGraph(V);
java.util.Collections.sort(allEdge);
DSU uf = new DSU(V);
for(Edge e:allEdge){
if(!uf.same(e.getLeftVertex(), e.getRightVertex())){
uf.merge(e.getLeftVertex(), e.getRightVertex());
ans.addEdge(e.getLeftVertex(), e.getRightVertex(), e.getLength());
}
}
if(uf.groups().size() > 1) throw new Exception("kruskal algorithm: the graph is disconnected");
return ans;
}
public String toString(){return allEdge.toString();}
}
class Pair<S extends Comparable<S>, T extends Comparable<T>> implements Comparable<Pair<S,T>>{
S first;
T second;
public Pair(S s, T t){
first = s;
second = t;
}
public S getFirst(){return first;}
public T getSecond(){return second;}
public boolean equals(Object another){
if(this==another) return true;
if(!(another instanceof Pair)) return false;
Pair otherPair = (Pair)another;
return this.first.equals(otherPair.first) && this.second.equals(otherPair.second);
}
public int compareTo(Pair<S,T> another){
java.util.Comparator<Pair<S,T>> comp1 = java.util.Comparator.comparing(Pair::getFirst);
java.util.Comparator<Pair<S,T>> comp2 = comp1.thenComparing(Pair::getSecond);
return comp2.compare(this, another);
}
public int hashCode(){
return first.hashCode() * 10007 + second.hashCode();
}
public String toString(){
return String.format("(%s, %s)", first, second);
}
}
class DSU {
private int n;
private int[] parentOrSize;
public DSU(int n) {
this.n = n;
this.parentOrSize = new int[n];
java.util.Arrays.fill(parentOrSize, -1);
}
int merge(int a, int b) {
if (!(0 <= a && a < n))
throw new IndexOutOfBoundsException("a=" + a);
if (!(0 <= b && b < n))
throw new IndexOutOfBoundsException("b=" + b);
int x = leader(a);
int y = leader(b);
if (x == y) return x;
if (-parentOrSize[x] < -parentOrSize[y]) {
int tmp = x;
x = y;
y = tmp;
}
parentOrSize[x] += parentOrSize[y];
parentOrSize[y] = x;
return x;
}
boolean same(int a, int b) {
if (!(0 <= a && a < n))
throw new IndexOutOfBoundsException("a=" + a);
if (!(0 <= b && b < n))
throw new IndexOutOfBoundsException("b=" + b);
return leader(a) == leader(b);
}
int leader(int a) {
if (parentOrSize[a] < 0) {
return a;
} else {
parentOrSize[a] = leader(parentOrSize[a]);
return parentOrSize[a];
}
}
int size(int a) {
if (!(0 <= a && a < n))
throw new IndexOutOfBoundsException("" + a);
return -parentOrSize[leader(a)];
}
java.util.ArrayList<java.util.ArrayList<Integer>> groups() {
int[] leaderBuf = new int[n];
int[] groupSize = new int[n];
for (int i = 0; i < n; i++) {
leaderBuf[i] = leader(i);
groupSize[leaderBuf[i]]++;
}
java.util.ArrayList<java.util.ArrayList<Integer>> result = new java.util.ArrayList<>(n);
for (int i = 0; i < n; i++) {
result.add(new java.util.ArrayList<>(groupSize[i]));
}
for (int i = 0; i < n; i++) {
result.get(leaderBuf[i]).add(i);
}
result.removeIf(java.util.ArrayList::isEmpty);
return result;
}
}
class ContestScanner {
private final java.io.InputStream in;
private final byte[] buffer = new byte[1024];
private int ptr = 0;
private int buflen = 0;
private static final long LONG_MAX_TENTHS = 922337203685477580L;
private static final int LONG_MAX_LAST_DIGIT = 7;
private static final int LONG_MIN_LAST_DIGIT = 8;
public ContestScanner(java.io.InputStream in){
this.in = in;
}
public ContestScanner(){
this(System.in);
}
private boolean hasNextByte() {
if (ptr < buflen) {
return true;
}else{
ptr = 0;
try {
buflen = in.read(buffer);
} catch (java.io.IOException e) {
e.printStackTrace();
}
if (buflen <= 0) {
return false;
}
}
return true;
}
private int readByte() {
if (hasNextByte()) return buffer[ptr++]; else return -1;
}
private static boolean isPrintableChar(int c) {
return 33 <= c && c <= 126;
}
public boolean hasNext() {
while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
return hasNextByte();
}
public String next() {
if (!hasNext()) throw new java.util.NoSuchElementException();
StringBuilder sb = new StringBuilder();
int b = readByte();
while(isPrintableChar(b)) {
sb.appendCodePoint(b);
b = readByte();
}
return sb.toString();
}
public long nextLong() {
if (!hasNext()) throw new java.util.NoSuchElementException();
long n = 0;
boolean minus = false;
int b = readByte();
if (b == '-') {
minus = true;
b = readByte();
}
if (b < '0' || '9' < b) {
throw new NumberFormatException();
}
while (true) {
if ('0' <= b && b <= '9') {
int digit = b - '0';
if (n >= LONG_MAX_TENTHS) {
if (n == LONG_MAX_TENTHS) {
if (minus) {
if (digit <= LONG_MIN_LAST_DIGIT) {
n = -n * 10 - digit;
b = readByte();
if (!isPrintableChar(b)) {
return n;
} else if (b < '0' || '9' < b) {
throw new NumberFormatException(
String.format("%d%s... is not number", n, Character.toString(b))
);
}
}
} else {
if (digit <= LONG_MAX_LAST_DIGIT) {
n = n * 10 + digit;
b = readByte();
if (!isPrintableChar(b)) {
return n;
} else if (b < '0' || '9' < b) {
throw new NumberFormatException(
String.format("%d%s... is not number", n, Character.toString(b))
);
}
}
}
}
throw new ArithmeticException(
String.format("%s%d%d... overflows long.", minus ? "-" : "", n, digit)
);
}
n = n * 10 + digit;
}else if(b == -1 || !isPrintableChar(b)){
return minus ? -n : n;
}else{
throw new NumberFormatException();
}
b = readByte();
}
}
public int nextInt() {
long nl = nextLong();
if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
return (int) nl;
}
public double nextDouble() {
return Double.parseDouble(next());
}
public long[] nextLongArray(int length){
long[] array = new long[length];
for(int i=0; i<length; i++) array[i] = this.nextLong();
return array;
}
public long[] nextLongArray(int length, java.util.function.LongUnaryOperator map){
long[] array = new long[length];
for(int i=0; i<length; i++) array[i] = map.applyAsLong(this.nextLong());
return array;
}
public int[] nextIntArray(int length){
int[] array = new int[length];
for(int i=0; i<length; i++) array[i] = this.nextInt();
return array;
}
public int[] nextIntArray(int length, java.util.function.IntUnaryOperator map){
int[] array = new int[length];
for(int i=0; i<length; i++) array[i] = map.applyAsInt(this.nextInt());
return array;
}
public double[] nextDoubleArray(int length){
double[] array = new double[length];
for(int i=0; i<length; i++) array[i] = this.nextDouble();
return array;
}
public double[] nextDoubleArray(int length, java.util.function.DoubleUnaryOperator map){
double[] array = new double[length];
for(int i=0; i<length; i++) array[i] = map.applyAsDouble(this.nextDouble());
return array;
}
public long[][] nextLongMatrix(int height, int width){
long[][] mat = new long[height][width];
for(int h=0; h<height; h++) for(int w=0; w<width; w++){
mat[h][w] = this.nextLong();
}
return mat;
}
public int[][] nextIntMatrix(int height, int width){
int[][] mat = new int[height][width];
for(int h=0; h<height; h++) for(int w=0; w<width; w++){
mat[h][w] = this.nextInt();
}
return mat;
}
public double[][] nextDoubleMatrix(int height, int width){
double[][] mat = new double[height][width];
for(int h=0; h<height; h++) for(int w=0; w<width; w++){
mat[h][w] = this.nextDouble();
}
return mat;
}
public char[][] nextCharMatrix(int height, int width){
char[][] mat = new char[height][width];
for(int h=0; h<height; h++){
String s = this.next();
for(int w=0; w<width; w++){
mat[h][w] = s.charAt(w);
}
}
return mat;
}
}
class ContestPrinter extends java.io.PrintWriter{
public ContestPrinter(java.io.PrintStream stream){
super(stream);
}
public ContestPrinter(){
super(System.out);
}
private static String dtos(double x, int n) {
StringBuilder sb = new StringBuilder();
if(x < 0){
sb.append('-');
x = -x;
}
x += Math.pow(10, -n)/2;
sb.append((long)x);
sb.append(".");
x -= (long)x;
for(int i = 0;i < n;i++){
x *= 10;
sb.append((int)x);
x -= (int)x;
}
return sb.toString();
}
@Override
public void print(float f){
super.print(dtos(f, 20));
}
@Override
public void println(float f){
super.println(dtos(f, 20));
}
@Override
public void print(double d){
super.print(dtos(d, 20));
}
@Override
public void println(double d){
super.println(dtos(d, 20));
}
public void printArray(int[] array, String separator){
int n = array.length;
if(n==0){
super.println();
return;
}
for(int i=0; i<n-1; i++){
super.print(array[i]);
super.print(separator);
}
super.println(array[n-1]);
}
public void printArray(int[] array){
this.printArray(array, " ");
}
public void printArray(int[] array, String separator, java.util.function.IntUnaryOperator map){
int n = array.length;
if(n==0){
super.println();
return;
}
for(int i=0; i<n-1; i++){
super.print(map.applyAsInt(array[i]));
super.print(separator);
}
super.println(map.applyAsInt(array[n-1]));
}
public void printArray(int[] array, java.util.function.IntUnaryOperator map){
this.printArray(array, " ", map);
}
public void printArray(long[] array, String separator){
int n = array.length;
if(n==0){
super.println();
return;
}
for(int i=0; i<n-1; i++){
super.print(array[i]);
super.print(separator);
}
super.println(array[n-1]);
}
public void printArray(long[] array){
this.printArray(array, " ");
}
public void printArray(long[] array, String separator, java.util.function.LongUnaryOperator map){
int n = array.length;
if(n==0){
super.println();
return;
}
for(int i=0; i<n-1; i++){
super.print(map.applyAsLong(array[i]));
super.print(separator);
}
super.println(map.applyAsLong(array[n-1]));
}
public void printArray(long[] array, java.util.function.LongUnaryOperator map){
this.printArray(array, " ", map);
}
}