結果
問題 | No.872 All Tree Path |
ユーザー |
|
提出日時 | 2019-08-31 00:39:19 |
言語 | Java (openjdk 23) |
結果 |
AC
|
実行時間 | 540 ms / 3,000 ms |
コード長 | 2,882 bytes |
コンパイル時間 | 5,364 ms |
コンパイル使用メモリ | 78,260 KB |
実行使用メモリ | 120,448 KB |
最終ジャッジ日時 | 2024-11-22 06:36:47 |
合計ジャッジ時間 | 8,460 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 18 |
ソースコード
import java.util.*;import java.io.*;public class Main {static int n;static ArrayList<Edge>[] edges;static int[] cnt;static long ret = 0;public static void main(String[] args){FastScanner scanner = new FastScanner();n = scanner.nextInt();int[] u = new int[n];int[] v = new int[n];int[] w = new int[n];edges = new ArrayList[n];cnt = new int[n];for(int i = 0; i < n; i++){edges[i] = new ArrayList<Edge>();}for(int i = 0; i < n-1; i++){u[i] = scanner.nextInt()-1;v[i] = scanner.nextInt()-1;w[i] = scanner.nextInt();edges[u[i]].add(new Edge(v[i],w[i]));edges[v[i]].add(new Edge(u[i],w[i]));}dfs(0,-1);System.out.println(ret*2L);}public static long dfs(int i, int parent){cnt[i] = 1;int r = 0;for(Edge e : edges[i]){if(e.to == parent){r = e.cost;}else{cnt[i] += dfs(e.to,i);}}ret += 1L*r*cnt[i]*(n-cnt[i]);return cnt[i];}public static class Edge{int to;int cost;Edge(int to, int cost){this.to = to;this.cost = cost;}}private static class FastScanner {private final InputStream in = System.in;private final byte[] buffer = new byte[1024];private int ptr = 0;private int buflen = 0;private boolean hasNextByte() {if (ptr < buflen) {return true;}else{ptr = 0;try {buflen = in.read(buffer);} catch (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 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 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') {n *= 10;n += b - '0';}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());}}}