結果

問題 No.1079 まお
コンテスト
ユーザー hos.lyric
提出日時 2020-06-12 23:00:00
言語 D
(dmd 2.109.1)
結果
WA  
実行時間 -
コード長 3,992 bytes
コンパイル時間 862 ms
コンパイル使用メモリ 131,460 KB
実行使用メモリ 50,448 KB
最終ジャッジ日時 2024-06-22 07:21:44
合計ジャッジ時間 17,340 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge1
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 18 WA * 12
権限があれば一括ダウンロードができます

ソースコード

diff # 

import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }




void main() {
  try {
    for (; ; ) {
      const N = readInt();
      const K = readLong();
      auto A = new long[N];
      foreach (i; 0 .. N) {
        A[i] = readLong();
      }
      
      long ans;
      foreach (i; 0 .. N) {
        if (A[i] + A[i] == K) {
          ans += 1;
        }
      }
      
      void solve(int l, int r) {
        if (r - l <= 1) {
          return;
        }
        const mid = (l + r) / 2;
        solve(l, mid);
        solve(mid, r);
        alias Entry = Tuple!(long, "val", int, "pos");
        Entry[] ps, qs;
        {
          long mn = long.max;
          int cnt;
          foreach_reverse (i; l .. mid) {
            if (chmin(mn, A[i])) cnt = 0;
            if (mn == A[i]) ++cnt;
            if (cnt == 1) ps ~= Entry(mn, i);
          }
        }
        {
          long mn = long.max;
          int cnt;
          foreach (i; mid .. r) {
            if (chmin(mn, A[i])) cnt = 0;
            if (mn == A[i]) ++cnt;
            if (cnt == 1) qs ~= Entry(mn, i);
          }
        }
        long[] vals;
        foreach (ref p; ps) vals ~= p.val;
        foreach (ref q; qs) vals ~= q.val;
        vals = vals.sort.uniq.array;
        debug {
          writeln("solve ", l, " ", mid, " ", r);
          writeln("  ps = ", ps);
          writeln("  qs = ", qs);
        }
        const psLen = cast(int)(ps.length);
        const qsLen = cast(int)(qs.length);
        int kp, kq;
        long[long] s0P, s1P, s0Q, s1Q;
        foreach_reverse (val; vals) {
          int lp, lq;
          for (lp = kp; lp < psLen && ps[lp].val == val; ++lp) {}
          for (lq = kq; lq < qsLen && qs[lq].val == val; ++lq) {}
          debug {
            writeln("  ", val, " ", [kp, lp], " ", [kq, lq]);
          }
          foreach (m; kp .. lp) {
            const i = ps[m].pos;
            if ((K - A[i]) in s0Q) {
              debug {
                writeln("    P ", ps[m], " ", (s1Q[K - A[i]] - s0Q[K - A[i]] * (i - 1)));
              }
              ans += (s1Q[K - A[i]] - s0Q[K - A[i]] * (i - 1));
            }
          }
          foreach (m; kq .. lq) {
            const i = qs[m].pos;
            if ((K - A[i]) in s0P) {
              debug {
                writeln("    Q ", qs[m], " ", (s0P[K - A[i]] * (i + 1) - s1P[K - A[i]]));
              }
              ans += (s0P[K - A[i]] * (i + 1) - s1P[K - A[i]]);
            }
          }
          foreach (m; kp .. lp) {
            const i = ps[m].pos;
            s0P[A[i]] += 1;
            s1P[A[i]] += i;
          }
          foreach (m; kq .. lq) {
            const i = qs[m].pos;
            s0Q[A[i]] += 1;
            s1Q[A[i]] += i;
          }
          kp = lp;
          kq = lq;
        }
      }
      
      solve(0, N);
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}
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