結果
問題 |
No.3091 The Little Match Boy
|
ユーザー |
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提出日時 | 2025-04-07 15:48:04 |
言語 | Java (openjdk 23) |
結果 |
AC
|
実行時間 | 179 ms / 2,000 ms |
コード長 | 3,609 bytes |
コンパイル時間 | 3,433 ms |
コンパイル使用メモリ | 82,216 KB |
実行使用メモリ | 59,628 KB |
最終ジャッジ日時 | 2025-04-07 15:48:20 |
合計ジャッジ時間 | 14,204 ms |
ジャッジサーバーID (参考情報) |
judge4 / judge1 |
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ファイルパターン | 結果 |
---|---|
other | AC * 62 |
ソースコード
import java.io.*; import java.util.*; import java.util.function.*; import java.util.stream.*; public class Main { public static void main(String[] args) throws Exception { FastScanner sc = new FastScanner(); int n = sc.nextInt(); int m = sc.nextInt(); int[] place = IntStream.range(0, n).toArray(); Set<Pair> ans = new HashSet<>(); while (m-- > 0) { int x = sc.nextInt(); ans.add(new Pair(place[x - 1], place[x])); int tmp = place[x - 1]; place[x - 1] = place[x]; place[x] = tmp; } System.out.println(ans.size()); } static class Pair { int a; int b; public Pair(int x, int y) { a = Math.min(x, y); b = Math.max(x, y); } public int hashCode() { return Objects.hash(a, b); } public boolean equals(Object o) { Pair p = (Pair)o; return a == p.a && b == p.b; } } } class FastScanner { private DataInputStream din; private byte[] buffer; private int bufferPointer, bytesRead; private static final int BUFFER_SIZE = 1 << 16; // 65,536 バイト public FastScanner() { din = new DataInputStream(System.in); buffer = new byte[BUFFER_SIZE]; bufferPointer = bytesRead = 0; } private byte read() { try { if (bufferPointer == bytesRead) { bytesRead = din.read(buffer, 0, BUFFER_SIZE); if (bytesRead == -1) return -1; bufferPointer = 0; } return buffer[bufferPointer++]; } catch (IOException e) { throw new RuntimeException(e); } } public String next() { byte b = read(); // 空白文字を読み飛ばす while (isSpaceChar(b)) { b = read(); } StringBuilder sb = new StringBuilder(); while (!isSpaceChar(b)) { sb.append((char) b); b = read(); } return sb.toString(); } public int nextInt() { int ret = 0; byte c = read(); while (isSpaceChar(c)) c = read(); boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10 + c - '0'; c = read(); } while (!isSpaceChar(c)); return neg ? -ret : ret; } public long nextLong() { long ret = 0; byte c = read(); while (isSpaceChar(c)) c = read(); boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10L + c - '0'; c = read(); } while (!isSpaceChar(c)); return neg ? -ret : ret; } public double nextDouble() { double ret = 0, div = 1; byte c = read(); while (isSpaceChar(c)) c = read(); boolean neg = (c == '-'); if (neg) c = read(); do { ret = ret * 10 + c - '0'; c = read(); } while (!isSpaceChar(c) && c != '.'); if (c == '.') { while (!isSpaceChar(c = read())) { ret += (c - '0') / (div *= 10); } } return neg ? -ret : ret; } private boolean isSpaceChar(byte c) { return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } public void close() { try { if (din != null) din.close(); } catch (IOException e) { throw new RuntimeException(e); } } }