結果

問題 No.1364 [Renaming] Road to Cherry from Zelkova
コンテスト
ユーザー hos.lyric
提出日時 2021-01-22 22:03:31
言語 D
(dmd 2.109.1)
結果
AC  
実行時間 274 ms / 2,500 ms
コード長 4,557 bytes
コンパイル時間 1,898 ms
コンパイル使用メモリ 157,188 KB
実行使用メモリ 30,080 KB
最終ジャッジ日時 2024-06-22 10:42:13
合計ジャッジ時間 13,127 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge4
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 3
other AC * 45
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)); }


struct ModInt(int M_) {
  import std.conv : to;
  alias M = 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 if (op == "/") { this *= a.inv(); }
    else static assert(false);
    return this;
  }
  ref ModInt opOpAssign(string op)(long a) {
    static if (op == "^^") {
      if (a < 0) return (this = inv()^^(-a));
      ModInt t2 = this, te = ModInt(1);
      for (long e = a; e > 0; e >>= 1) {
        if (e & 1) te *= t2;
        t2 *= t2;
      }
      x = cast(int)(te.x);
      return this;
    } else return mixin("this " ~ op ~ "= ModInt(a)");
  }
  ModInt inv() const {
    int a = x, b = M, y = 1, z = 0, t;
    for (; ; ) {
      t = a / b; a -= t * b;
      if (a == 0) {
        assert(b == 1 || b == -1);
        return ModInt(b * z);
      }
      y -= t * z;
      t = b / a; b -= t * a;
      if (b == 0) {
        assert(a == 1 || a == -1);
        return ModInt(a * y);
      }
      z -= t * y;
    }
  }
  ModInt opUnary(string op: "-")() const { 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");
  }
  bool opCast(T: bool)() const { return (x != 0); }
  string toString() const { return x.to!string; }
}

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


int N, M;
int[] A, B;
long[] C, D;

int[][][] G;
bool[][] vis;

void dfs(int s, int u) {
  if (!vis[s][u]) {
    vis[s][u] = true;
    foreach (i; G[s][u]) {
      const v = A[i] ^ B[i] ^ u;
      dfs(s, v);
    }
  }
}

int[] col;
Mint[] dp0, dp1;
bool solve(int u) {
  col[u] = 1;
  dp0[u] = (u == N - 1) ? 1 : 0;
  dp1[u] = 0;
  foreach (i; G[0][u]) {
    const v = B[i];
    if (vis[0][v] && vis[1][v]) {
      if (col[v] == 0) {
        if (!solve(v)) {
          return false;
        }
      } else if (col[v] == 1) {
        return false;
      }
      dp0[u] += dp0[v] * D[i];
      dp1[u] += dp0[v] * D[i] * C[i] + D[i] * dp1[v];
    }
  }
  col[u] = 2;
  return true;
}

void main() {
  try {
    for (; ; ) {
      N = readInt() + 1;
      M = readInt();
      A = new int[M];
      B = new int[M];
      C = new long[M];
      D = new long[M];
      foreach (i; 0 .. M) {
        A[i] = readInt();
        B[i] = readInt();
        C[i] = readLong();
        D[i] = readLong();
      }
      
      G = new int[][][](2, N);
      foreach (i; 0 .. M) {
        G[0][A[i]] ~= i;
        G[1][B[i]] ~= i;
      }
      vis = new bool[][](2, N);
      dfs(0, 0);
      dfs(1, N - 1);
      debug {
        writeln("vis = ", vis);
      }
      
      if (vis[1][0]) {
        col = new int[N];
        dp0 = new Mint[N];
        dp1 = new Mint[N];
        const res = solve(0);
        debug {
          writeln("dp0 = ", dp0);
          writeln("dp1 = ", dp1);
        }
        if (res) {
          writeln(dp1[0]);
        } else {
          writeln("INF");
        }
      } else {
        writeln(0);
      }
    }
  } catch (EOFException e) {
  }
}
0