結果

問題 No.1124 Earthquake Safety
ユーザー 👑 hos.lyric
提出日時 2020-07-22 22:01:53
言語 D
(dmd 2.109.1)
結果
AC  
実行時間 1,143 ms / 3,000 ms
コード長 5,976 bytes
コンパイル時間 1,492 ms
コンパイル使用メモリ 155,776 KB
実行使用メモリ 222,152 KB
最終ジャッジ日時 2024-06-22 07:46:55
合計ジャッジ時間 44,520 ms
ジャッジサーバーID
(参考情報)
judge5 / judge4
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ファイルパターン 結果
other AC * 58
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ソースコード

diff #
プレゼンテーションモードにする

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 = 1_000_000_007;
alias Mint = ModInt!MO;
int N;
int[] A, B;
int[][] G;
int[] par;
Mint[][] dp, DP;
void dfs(int u, int p) {
par[u] = p;
foreach (i; G[u]) {
const v = A[i] ^ B[i] ^ u;
if (v != p) {
dfs(v, u);
}
}
auto crt = [Mint(1), Mint(0)];
foreach (i; G[u]) {
const v = A[i] ^ B[i] ^ u;
if (v != p) {
auto nxt = new Mint[2];
nxt[0] += crt[0] * (2 * dp[v][0]);
nxt[1] += crt[0] * dp[v][1];
nxt[1] += crt[1] * (2 * dp[v][0]);
crt = nxt;
}
}
dp[u] = crt;
dp[u][1] += dp[u][0];
}
void DFS(int u, int p) {
int[] vs;
foreach (i; G[u]) {
const v = A[i] ^ B[i] ^ u;
if (v != p) {
vs ~= v;
}
}
const len = cast(int)(vs.length);
auto ls = new Mint[][](len + 1, 2);
auto rs = new Mint[][](len + 1, 2);
ls[0] = (p != -1) ? [2 * DP[u][0], DP[u][1]] : [Mint(1), Mint(0)];
foreach (j; 0 .. len) {
ls[j + 1][0] += ls[j][0] * (2 * dp[vs[j]][0]);
ls[j + 1][1] += ls[j][0] * dp[vs[j]][1];
ls[j + 1][1] += ls[j][1] * (2 * dp[vs[j]][0]);
}
rs[len] = [Mint(1), Mint(0)];
foreach_reverse (j; 0 .. len) {
rs[j][0] += rs[j + 1][0] * (2 * dp[vs[j]][0]);
rs[j][1] += rs[j + 1][0] * dp[vs[j]][1];
rs[j][1] += rs[j + 1][1] * (2 * dp[vs[j]][0]);
}
foreach (j; 0 .. len) {
DP[vs[j]] = new Mint[2];
DP[vs[j]][0] += ls[j][0] * rs[j + 1][0];
DP[vs[j]][1] += ls[j][0] * rs[j + 1][1];
DP[vs[j]][1] += ls[j][1] * rs[j + 1][0];
DP[vs[j]][1] += DP[vs[j]][0];
}
foreach (i; G[u]) {
const v = A[i] ^ B[i] ^ u;
if (v != p) {
DFS(v, u);
}
}
}
void main() {
try {
for (; ; ) {
N = readInt();
A = new int[N - 1];
B = new int[N - 1];
foreach (i; 0 .. N - 1) {
A[i] = readInt() - 1;
B[i] = readInt() - 1;
}
G = new int[][N];
foreach (i; 0 .. N - 1) {
G[A[i]] ~= i;
G[B[i]] ~= i;
}
par = new int[N];
dp = new Mint[][N];
DP = new Mint[][N];
const rt = 0;
dfs(rt, -1);
DFS(rt, -1);
debug {
writeln("dp = ", dp);
writeln("DP = ", DP);
}
Mint ans;
foreach (u; 0 .. N) {
auto crt = new Mint[4];
crt[0] = 1;
if (par[u] != -1) {
auto nxt = new Mint[4];
foreach (x; 0 .. 4) {
nxt[x] += crt[x] * (2 * DP[u][0]);
if (x + 1 < 4) {
nxt[x + 1] += crt[x] * DP[u][1];
}
}
crt = nxt;
}
foreach (i; G[u]) {
const v = A[i] ^ B[i] ^ u;
if (v != par[u]) {
auto nxt = new Mint[4];
foreach (x; 0 .. 4) {
nxt[x] += crt[x] * (2 * dp[v][0]);
if (x + 1 < 4) {
nxt[x + 1] += crt[x] * dp[v][1];
}
}
crt = nxt;
}
}
debug {
writeln(u, ": ", crt);
}
ans += 6 * crt[3];
ans += 6 * crt[2];
ans += 3 * crt[1];
ans += 1 * crt[0];
}
writeln(ans);
}
} catch (EOFException e) {
}
}
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