結果
問題 | No.1075 木の上の山 |
ユーザー |
👑 |
提出日時 | 2020-06-05 22:22:49 |
言語 | D (dmd 2.109.1) |
結果 |
AC
|
実行時間 | 71 ms / 2,000 ms |
コード長 | 5,294 bytes |
コンパイル時間 | 1,749 ms |
コンパイル使用メモリ | 156,216 KB |
実行使用メモリ | 37,628 KB |
最終ジャッジ日時 | 2024-06-22 07:17:08 |
合計ジャッジ時間 | 3,682 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 30 |
ソースコード
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, K;int[] A, B;Mint[] mul(Mint[] fs, Mint[] gs) {auto hs = new Mint[K];foreach (k; 0 .. K) {hs[k] = fs[k] * gs[k];}return hs;}Mint[] up(Mint[] fs) {auto gs = fs.dup;foreach (k; 1 .. K) {gs[k] += gs[k - 1];}return gs;}Mint[] shift(Mint[] fs) {return [Mint(0)] ~ fs[0 .. K - 1];}int[][] G;int zeit;int[] par, ord;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);}}Mint[] fs = new Mint[K];fs[] = Mint(1);foreach (i; G[u]) {const v = A[i] ^ B[i] ^ u;if (v != p) {fs = mul(fs, dp[v]);}}dp[u] = up(fs);}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];auto rs = new Mint[][len + 1];ls[0] = new Mint[K];ls[0][] = Mint(1);rs[len] = new Mint[K];rs[len][] = Mint(1);if (p != -1) {rs[len] = DP[u];}foreach (j; 0 .. len) {ls[j + 1] = mul(ls[j], dp[vs[j]]);}foreach_reverse (j; 0 .. len) {rs[j] = mul(dp[vs[j]], rs[j + 1]);}foreach (j; 0 .. len) {DP[vs[j]] = up(mul(ls[j], rs[j + 1]));}foreach (j; 0 .. len) {DFS(vs[j], u);}}void main() {try {for (; ; ) {N = readInt();K = 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 = N - 1;dfs(rt, -1);DFS(rt, -1);debug {writeln("rt = ", rt);writeln("dp = ", dp);writeln("DP = ", DP);}Mint ans;foreach (u; 0 .. N) {Mint[] fs = new Mint[K];fs[] = Mint(1);if (u != rt) {fs = shift(DP[u]);}foreach (i; G[u]) {const v = A[i] ^ B[i] ^ u;if (v != par[u]) {fs = mul(fs, dp[v]);}}debug {writeln(u, ": ", fs);}ans += fs.sum;}writeln(ans);}} catch (EOFException e) {}}