結果

問題 No.895 MESE
ユーザー 👑 hos.lyrichos.lyric
提出日時 2019-09-28 11:07:19
言語 D
(dmd 2.107.1)
結果
AC  
実行時間 53 ms / 2,000 ms
コード長 3,534 bytes
コンパイル時間 1,431 ms
コンパイル使用メモリ 151,360 KB
実行使用メモリ 24,692 KB
最終ジャッジ日時 2023-09-04 02:51:24
合計ジャッジ時間 3,802 ms
ジャッジサーバーID
（参考情報） 		judge15 / judge13
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 34 ms
23,844 KB
testcase_01 AC 31 ms
22,608 KB
testcase_02 AC 34 ms
21,004 KB
testcase_03 AC 32 ms
23,968 KB
testcase_04 AC 34 ms
21,868 KB
testcase_05 AC 30 ms
22,340 KB
testcase_06 AC 30 ms
20,496 KB
testcase_07 AC 31 ms
23,104 KB
testcase_08 AC 30 ms
21,324 KB
testcase_09 AC 30 ms
20,944 KB
testcase_10 AC 32 ms
24,692 KB
testcase_11 AC 31 ms
20,956 KB
testcase_12 AC 31 ms
20,508 KB
testcase_13 AC 41 ms
21,660 KB
testcase_14 AC 42 ms
20,916 KB
testcase_15 AC 47 ms
20,876 KB
testcase_16 AC 42 ms
21,712 KB
testcase_17 AC 37 ms
23,076 KB
testcase_18 AC 49 ms
21,260 KB
testcase_19 AC 47 ms
20,780 KB
testcase_20 AC 52 ms
20,364 KB
testcase_21 AC 49 ms
23,464 KB
testcase_22 AC 52 ms
20,612 KB
testcase_23 AC 48 ms
21,068 KB
testcase_24 AC 48 ms
22,496 KB
testcase_25 AC 52 ms
20,048 KB
testcase_26 AC 49 ms
22,040 KB
testcase_27 AC 53 ms
21,260 KB
testcase_28 AC 48 ms
22,164 KB
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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.complex, std.container, std.math, 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)); }

struct ModInt(long M) {
  int x;
  this(ModInt a) { x = a.x; }
  this(long a) { x = cast(int)(a % M); if (x < 0) x += M; }
  ref ModInt opAssign(long a) { return (this = ModInt(a)); }
  ref ModInt opOpAssign(string op)(ModInt a) {
    static if (op == "+") { x += a.x; if (x >= M) x -= M; }
    else static if (op == "-") { x -= a.x; if (x < 0) x += M; }
    else static if (op == "*") { x = cast(int)((cast(long)(x) * a.x) % M); }
    else static assert(false);
    return this;
  }
  ref ModInt opOpAssign(string op)(long a) {
    static if (op == "^^") {
      ModInt t2 = this, te = ModInt(1);
      for (long e = a; e; e >>= 1) {
        if (e & 1) te *= t2;
        t2 *= t2;
      }
      x = cast(int)(te.x);
      return this;
    } else return mixin("this " ~ op ~ "= ModInt(a)");
  }
  ModInt opUnary(string op)() const if (op == "-") { return ModInt(-x); }
  ModInt opBinary(string op, T)(T a) const { return mixin("ModInt(this) " ~ op ~ "= a"); }
  ModInt opBinaryRight(string op)(long a) const { return mixin("ModInt(a) " ~ op ~ "= this"); }
  string toString() const { return x.to!string; }
}

enum MO = 10L^^9 + 7;
alias Mint = ModInt!MO;

enum LIM = 7 * 10^^5;

long[] inv, fac, invFac;
void prepare() {
  inv = new long[LIM];
  fac = new long[LIM];
  invFac = new long[LIM];
  inv[1] = 1;
  foreach (i; 2 .. LIM) {
    inv[i] = MO - ((MO / i) * inv[cast(size_t)(MO % i)]) % MO;
  }
  fac[0] = invFac[0] = 1;
  foreach (i; 1 .. LIM) {
    fac[i] = (fac[i - 1] * i) % MO;
    invFac[i] = (invFac[i - 1] * inv[i]) % MO;
  }
}
long binom(long n, long k) {
  if (0 <= k && k <= n) {
    assert(n < LIM);
    return fac[cast(size_t)(n)] * invFac[cast(size_t)(k)] % MO * invFac[cast(size_t)(n - k)] % MO;
  } else {
    return 0;
  }
}


void main() {
  prepare();
  
  try {
    for (; ; ) {
      const A = readInt();
      const B = readInt();
      const C = readInt();
      
      Mint ans;
      Mint two = 1;
      foreach (k; 0 .. A + B + C - 2) {
        if (k >= C - 1) {
          Mint tmp = binom(A - 1 + B, A - 1);
          if (k - (C - 1) >= B) tmp -= binom(k - (C - 1), B);
          assert(!(k - (C - 1) >= A + B));
          tmp *= binom(k, C - 1);
          ans += two * tmp;
          if (k > 0) {
            ans += (two - 1) * tmp * (C - 1) * inv[k];
          }
        }
        two *= 2;
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}
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