結果

問題 No.1507 Road Blocked
ユーザー te-sh
提出日時 2021-06-08 15:42:03
言語 D
(dmd 2.109.1)
結果
AC  
実行時間 218 ms / 2,000 ms
コード長 10,992 bytes
コンパイル時間 2,369 ms
コンパイル使用メモリ 218,792 KB
実行使用メモリ 14,880 KB
最終ジャッジ日時 2024-06-22 11:27:32
合計ジャッジ時間 10,020 ms
ジャッジサーバーID
(参考情報)
judge5 / judge2
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 * 30
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 #
プレゼンテーションモードにする

// URL: https://yukicoder.me/problems/no/1507
import std;
version(unittest) {} else
void main()
{
int N; io.getV(N);
auto g = Graph(N);
foreach (_; 0..N-1) {
int ui, vi; io.getV(ui, vi); --ui; --vi;
g.addEdgeB(ui, vi);
}
auto a = SList!int(0), b = SList!int(0), visited = new bool[](N);
visited[0] = true;
while (!a.empty) {
auto u = a.front; a.removeFront();
foreach (v; g[u]) {
if (!visited[v]) {
a.insertFront(v);
b.insertFront(v);
visited[v] = true;
}
}
}
auto t = g.tree(0), c = new int[](N); c[] = 1;
while (!b.empty) {
auto u = b.front; b.removeFront();
if (u != 0) c[t.parent[u]] += c[u];
}
auto r = mint(0);
foreach (u; 1..N) {
auto d1 = mint(c[0]), d2 = mint(c[u]), d3 = mint(c[0] - c[u]);
r += (d3*(d3-1)/2 + d2*(d2-1)/2)/(d1*(d1-1)/2);
}
io.put(r/(N-1));
}
const mod = 998244353;
alias mint = ModInt!mod;
pure nothrow @safe
{
T powr(alias pred = "a*b", T, U)(const T a, U n, T one)
if (isIntegral!U)
{
auto b = T(a);
alias predFun = binaryFun!pred;
if (n == 0) return one;
auto r = one;
for (; n > 0; n >>= 1) {
if (n&1) r = predFun(r, b);
b = predFun(b, b);
}
return r;
}
T powr(alias pred = "a*b", T, U)(const T a, U n)
if (isIntegral!U)
{
return powr!(pred, T, U)(a, n, T(1));
}
}
pragma(inline) pure nothrow @nogc @safe
{
T cdiv(T)(const T a, const T b)
{
return (a+b-1)/b;
}
T pmod(T)(const T a, const T b)
{
return a >= 0 ? a%b : a%b+b;
}
}
pure nothrow @nogc @safe
{
ExtGcdResult!T extGcd(T)(const T a, const T b)
{
if (a == 0) {
return ExtGcdResult!T(T(b), T(0), T(1));
} else {
auto r = extGcd(b%a, a);
return ExtGcdResult!T(r.gcd, r.y-(b/a)*r.x, r.x);
}
}
private struct ExtGcdResult(T)
{
T gcd, x, y;
}
}
struct ModInt(int m)
{
pragma(inline) pure nothrow @nogc @safe
{
this(T)(T v)
if (isIntegral!T)
{
i = nm(v);
}
this(ref return scope const Mint v)
{
i = v.i;
}
bool opEquals(T)(T v) const
if (isIntegral!T)
{
return i == v;
}
bool opEquals(const Mint v) const
{
return i == v.i;
}
Mint opUnary(string op: "-")() const
{
return Mint(-i);
}
static if (m < int.max/2) {
Mint opBinary(string op: "+")(int r) const
{
Mint m;
m.i = nm(i+r);
return m;
}
Mint opBinary(string op: "+")(const Mint r) const
{
Mint m;
m.i = nmp(i+r.i);
return m;
}
ref Mint opOpAssign(string op: "+")(int r)
{
i = nm(i+r);
return this;
}
ref Mint opOpAssign(string op: "+")(const Mint r)
{
i = nmp(i+r.i);
return this;
}
} else {
Mint opBinary(string op: "+")(int r) const
{
Mint m;
m.i = nm(l+r);
return m;
}
Mint opBinary(string op: "+")(const Mint r) const
{
Mint m;
m.i = nmp(l+r.i);
return m;
}
ref Mint opOpAssign(string op: "+")(int r)
{
i = nm(l+r);
return this;
}
ref Mint opOpAssign(string op: "+")(const Mint r)
{
i = nmp(l+r.i);
return this;
}
}
Mint opBinary(string op: "-")(int r) const
{
return Mint(i-r);
}
Mint opBinary(string op: "-")(const Mint r) const
{
return Mint(i-r.i);
}
ref Mint opOpAssign(string op: "-")(int r)
{
i = nm(i-r);
return this;
}
ref Mint opOpAssign(string op: "-")(const Mint r)
{
i = nm(i-r.i);
return this;
}
Mint opBinary(string op, T)(T r) const
if ((op == "+" || op == "-") && isIntegral!T && !is(T == int))
{
return Mint(mixin("l"~op~"r"));
}
ref Mint opOpAssign(string op, T)(T r)
if ((op == "+" || op == "-") && isIntegral!T && !is(T == int))
{
i = nm(mixin("l"~op~"r"));
return this;
}
Mint opBinary(string op: "*", T)(T r) const
if (isIntegral!T)
{
Mint m;
m.i = nm(l*r);
return m;
}
Mint opBinary(string op: "*")(const Mint r) const
{
Mint m;
m.i = nmp(l*r.i);
return m;
}
ref Mint opOpAssign(string op: "*", T)(T r)
if (isIntegral!T)
{
i = nm(l*r);
return this;
}
ref Mint opOpAssign(string op: "*")(const Mint r)
{
i = nmp(l*r.i);
return this;
}
ref Mint opUnary(string op: "++")()
{
i = nmp(i+1);
return this;
}
ref Mint opUnary(string op: "--")()
{
i = nm(i-1);
return this;
}
Mint opBinary(string op: "^^", T)(T n)
if (isIntegral!T)
{
return powr(this, n, Mint(1));
}
Mint opBinary(string op: "/")(const Mint r) const
{
return Mint(l*r.inv.i);
}
ref Mint opOpAssign(string op: "/")(const Mint r)
{
i = nm(l*r.inv.i);
return this;
}
Mint opBinary(string op: "/", T)(T r) const
if (isIntegral!T)
{
return opBinary!op(Mint(r));
}
ref Mint opOpAssign(string op: "/", T)(T r)
if (isIntegral!T)
{
return opOpAssign!op(Mint(r));
}
Mint inv() const
{
return Mint(extGcd(i, m).x);
}
}
pure nothrow @nogc @safe
{
ref Mint opAssign(T)(T v)
if (isIntegral!T)
{
i = nm(v);
return this;
}
ref Mint opAssign(const Mint v)
{
i = v.i;
return this;
}
}
pure nothrow @safe
{
string toString() const
{
return i.to!string;
}
}
private
{
alias Mint = ModInt!m;
version(BigEndian) union { long l; struct { int i2; int i; } }
else union { long l; int i; }
pragma(inline) pure nothrow @nogc @safe
{
int nm(T)(T v) const
if (isIntegral!T)
{
return cast(int)pmod(v, m);
}
int nmp(T)(T v) const
if (isIntegral!T)
{
return cast(int)(v%m);
}
}
}
}
struct Graph
{
alias Node = int;
Node n;
Node[][] g;
alias g this;
pure nothrow @safe
{
this(Node n)
{
this.n = n;
g = new Node[][](n);
}
void addEdge(Node u, Node v)
in { assert(0 <= u && u < n && 0 <= v && v < n); }
do
{
g[u] ~= v;
}
void addEdgeB(Node u, Node v)
in { assert(0 <= u && u < n && 0 <= v && v < n); }
do
{
g[u] ~= v;
g[v] ~= u;
}
}
}
struct GraphW(W = int, W i = 10^^9)
{
alias Node = int, Wt = W, inf = i;
struct Edge
{
Node src, dst;
Wt wt;
alias cap = wt;
}
Node n;
Edge[][] g;
alias g this;
pure nothrow @safe
{
this(Node n)
{
this.n = n;
g = new Edge[][](n);
}
void addEdge(Node u, Node v, Wt w)
in { assert(0 <= u && u < n && 0 <= v && v < n); }
do
{
g[u] ~= Edge(u, v, w);
}
void addEdgeB(Node u, Node v, Wt w)
in { assert(0 <= u && u < n && 0 <= v && v < n); }
do
{
g[u] ~= Edge(u, v, w);
g[v] ~= Edge(v, u, w);
}
}
}
struct GraphM(W = int, W i = 10^^9)
{
alias Node = int, Wt = W, inf = i;
Node n;
Wt[][] g;
alias g this;
pure nothrow @safe
{
this(int n)
{
this.n = n;
g = new Wt[][](n, n);
}
static GraphM!(W, i) init(Node n)
{
auto g = GraphM!(W, i)(n);
foreach (i; 0..n) { g[i][] = inf; g[i][i] = 0; }
return g;
}
}
}
struct Tree(Graph)
{
alias Node = Graph.Node;
Graph g;
alias g this;
Node root;
Node[] parent, dfsOrder;
int[] size, depth;
pure nothrow @safe
{
this(Graph g, Node r)
in { assert(0 <= r && r < g.n); }
do
{
this.g = g;
this.root = r;
parent = new Node[](n);
depth = new int[](n);
depth[] = -1;
auto st = SList!UP(UP(r, r));
while (!st.empty) {
auto up = st.front; st.removeFront();
parent[up.u] = up.p;
depth[up.u] = depth[up.p] + 1;
dfsOrder ~= up.u;
foreach (v; g[up.u])
if (v != up.p) st.insertFront(UP(v, up.u));
}
size = new int[](n);
size[] = 1;
foreach_reverse (u; dfsOrder.drop(1))
size[parent[u]] += size[u];
}
auto children(Node u) const
in { assert(0 <= u && u < g.n); }
do
{
return g[u].filter!(v => v != parent[u]);
}
}
private
{
struct UP { Node u, p; }
}
}
pure nothrow @safe
{
auto tree(Graph, Node)(Graph g, Node r)
in { assert(0 <= r && r < g.n); }
do
{
return Tree!Graph(g, r);
}
}
auto io = IO!()();
struct IO(alias IN = stdin, alias OUT = stdout)
{
import core.stdc.stdlib : exit;
void getV(T...)(ref T v)
{
foreach (ref w; v) get(w);
}
void getA(T)(size_t n, ref T v)
if (hasAssignableElements!T)
{
v = new T(n);
foreach (ref w; v) get(w);
}
void getC(T...)(size_t n, ref T v)
if (allSatisfy!(hasAssignableElements, T))
{
foreach (ref w; v) w = new typeof(w)(n);
foreach (i; 0..n) foreach (ref w; v) get(w[i]);
}
void getM(T)(size_t r, size_t c, ref T v)
if (hasAssignableElements!T && hasAssignableElements!(ElementType!T))
{
v = new T(r);
foreach (ref w; v) getA(c, w);
}
template getS(E...)
{
void getS(T)(size_t n, ref T v)
{
v = new T(n);
foreach (ref w; v) foreach (e; E) mixin("get(w."~e~");");
}
}
const struct PutConf
{
bool newline = true, flush, exit;
string floatFormat = "%.10f", delimiter = " ";
}
void put(alias conf = "{}", T...)(T v)
{
putMain!conf(v);
}
void putB(alias conf = "{}", S, T)(bool c, S t, T f)
{
if (c) put!conf(t);
else put!conf(f);
}
void putRaw(T...)(T v)
{
OUT.write(v);
OUT.writeln;
}
private
{
dchar[] buf;
auto sp = (new dchar[](0)).splitter;
void nextLine()
{
IN.readln(buf);
sp = buf.splitter;
}
void get(T)(ref T v)
{
if (sp.empty) nextLine();
v = sp.front.to!T;
sp.popFront();
}
void putMain(alias conf, T...)(T v)
{
mixin("const PutConf c = "~conf~";");
foreach (i, w; v) {
putOne!conf(w);
if (i+1 < v.length) OUT.write(c.delimiter);
}
static if (c.newline) OUT.writeln;
static if (c.flush) OUT.flush();
static if (c.exit) exit(0);
}
void putOne(alias conf, T)(T v)
{
mixin("const PutConf c = "~conf~";");
static if (isInputRange!T && !isSomeString!T) putRange!conf(v);
else static if (isFloatingPoint!T) OUT.write(format(c.floatFormat, v));
else static if (hasMember!(T, "fprint")) v.fprint(OUT);
else OUT.write(v);
}
void putRange(alias conf, T)(T v)
{
mixin("const PutConf c = "~conf~";");
auto w = v;
while (!w.empty) {
putOne!conf(w.front); w.popFront();
if (!w.empty) OUT.write(c.delimiter);
}
}
}
}
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