結果

問題 No.827 総神童数
ユーザー mdj982mdj982
提出日時 2019-05-03 21:54:12
言語 C++14
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 263 ms / 2,000 ms
コード長 6,618 bytes
コンパイル時間 2,003 ms
コンパイル使用メモリ 184,904 KB
実行使用メモリ 26,104 KB
最終ジャッジ日時 2023-08-30 06:06:46
合計ジャッジ時間 8,282 ms
ジャッジサーバーID
(参考情報)
judge13 / judge14
このコードへのチャレンジ(β)

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 2 ms
4,376 KB
testcase_01 AC 1 ms
4,376 KB
testcase_02 AC 1 ms
4,380 KB
testcase_03 AC 1 ms
4,380 KB
testcase_04 AC 2 ms
4,376 KB
testcase_05 AC 1 ms
4,504 KB
testcase_06 AC 1 ms
4,380 KB
testcase_07 AC 1 ms
4,380 KB
testcase_08 AC 2 ms
4,376 KB
testcase_09 AC 263 ms
26,104 KB
testcase_10 AC 85 ms
10,792 KB
testcase_11 AC 5 ms
4,376 KB
testcase_12 AC 36 ms
6,848 KB
testcase_13 AC 206 ms
22,376 KB
testcase_14 AC 9 ms
4,376 KB
testcase_15 AC 79 ms
10,492 KB
testcase_16 AC 212 ms
19,236 KB
testcase_17 AC 251 ms
22,376 KB
testcase_18 AC 105 ms
12,600 KB
testcase_19 AC 256 ms
17,336 KB
testcase_20 AC 177 ms
14,060 KB
testcase_21 AC 119 ms
10,652 KB
testcase_22 AC 201 ms
15,072 KB
testcase_23 AC 3 ms
4,376 KB
testcase_24 AC 227 ms
16,056 KB
testcase_25 AC 165 ms
13,524 KB
testcase_26 AC 224 ms
16,032 KB
testcase_27 AC 148 ms
11,324 KB
testcase_28 AC 136 ms
11,420 KB
testcase_29 AC 114 ms
9,808 KB
testcase_30 AC 29 ms
5,220 KB
testcase_31 AC 79 ms
8,640 KB
testcase_32 AC 77 ms
8,532 KB
testcase_33 AC 242 ms
17,112 KB
testcase_34 AC 220 ms
15,932 KB
testcase_35 AC 81 ms
8,760 KB
testcase_36 AC 120 ms
10,620 KB
testcase_37 AC 155 ms
12,668 KB
testcase_38 AC 233 ms
16,796 KB
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 #

#include <bits/stdc++.h>
using namespace std;

using vi = vector<int>; using vvi = vector<vi>; using vvvi = vector<vvi>;
using ll = long long int;
using vll = vector<ll>; using vvll = vector<vll>; using vvvll = vector<vvll>;
using vd = vector<double>; using vvd = vector<vd>; using vvvd = vector<vvd>;
using P = pair<int, int>;
using Pll = pair<ll, ll>;
using cdouble = complex<double>;

const double eps = 1e-9;
const double INFD = numeric_limits<double>::infinity();
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#define Loopll(i, n) for(ll i = 0; i < (ll)n; i++)
#define Loop1(i, n) for(int i = 1; i <= (int)n; i++)
#define Loopll1(i, n) for(ll i = 1; i <= (ll)n; i++)
#define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--)
#define Looprll(i, n) for(ll i = (ll)n - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)n; i >= 1; i--)
#define Looprll1(i, n) for(ll i = (ll)n; i >= 1; i--)
#define Foreach(buf, container) for(auto buf : container)
#define Loopdiag(i, j, h, w, sum) for(int i = ((sum) >= (h) ? (h) - 1 : (sum)), j = (sum) - i; i >= 0 && j < (w); i--, j++)
#define Loopdiagr(i, j, h, w, sum) for(int j = ((sum) >= (w) ? (w) - 1 : (sum)), i = (sum) - j; j >= 0 && i < (h); j--, i++)
#define Loopdiagsym(i, j, h, w, gap) for (int i = ((gap) >= 0 ? (gap) : 0), j = i - (gap); i < (h) && j < (w); i++, j++)
#define Loopdiagsymr(i, j, h, w, gap) for (int i = ((gap) > (h) - (w) - 1 ? (h) - 1 : (w) - 1 + (gap)), j = i - (gap); i >= 0 && j >= 0; i--, j--)
#define Loopitr(itr, container) for(auto itr = container.begin(); itr != container.end(); itr++)
#define printv(vector) Loop(ex_i, vector.size()) { cout << vector[ex_i] << " "; } cout << endl;
#define printmx(matrix) Loop(ex_i, matrix.size()) { Loop(ex_j, matrix[ex_i].size()) { cout << matrix[ex_i][ex_j] << " "; } cout << endl; }
#define quickio() ios::sync_with_stdio(false); cin.tie(0);
#define bitmanip(m,val) static_cast<bitset<(int)m>>(val)
#define Comp(type_t) bool operator<(const type_t &another) const
#define fst first
#define snd second
bool nearlyeq(double x, double y) { return abs(x - y) < eps; }
bool inrange(ll x, ll t) { return x >= 0 && x < t; }
bool inrange(vll xs, ll t) { Foreach(x, xs) if (!(x >= 0 && x < t)) return false; return true; }
int ceillog2(ll x) { int ret = 0;	x--; while (x > 0) { ret++; x >>= 1; } return ret; }
ll rndf(double x) { return (ll)(x + (x >= 0 ? 0.5 : -0.5)); }
ll floorsqrt(ll x) { ll m = (ll)sqrt((double)x); return m + (m * m <= x ? 0 : -1); }
ll ceilsqrt(ll x) { ll m = (ll)sqrt((double)x); return m + (x <= m * m ? 0 : 1); }
ll rnddiv(ll a, ll b) { return (a / b + (a % b * 2 >= b ? 1 : 0)); }
ll ceildiv(ll a, ll b) { return (a / b + (a % b == 0 ? 0 : 1)); }
ll gcd(ll m, ll n) { if (n == 0) return m; else return gcd(n, m % n); }
ll lcm(ll m, ll n) { return m * n / gcd(m, n); }

/*******************************************************/

int n;
vvi lst;
vi cnt;
vi from;

void count(int a, int c) {
	cnt[a] = c;
	Foreach(b, lst[a]) {
		if (from[b] == INT_MIN) {
			from[b] = a;
			count(b, c + 1);
		}
	}
}

namespace mod_op {

	const ll MOD = (ll)1e9 + 7;

	class modll {
	private:
		ll val;
		ll modify(ll x) { ll ret = x % MOD; if (ret < 0) ret += MOD; return ret; }
		ll inv(ll x) {
			if (x == 0) return 1 / x;
			else if (x == 1) return 1;
			else return modify(inv(MOD % x) * modify(-MOD / x));
		}
	public:
		modll(ll init = 0) { val = modify(init); return; }
		modll(const modll& another) { val = another.val; return; }
		modll& operator=(const modll &another) { val = another.val; return *this; }
		modll operator+(const modll &x) { return modify(val + x.val); }
		modll operator-(const modll &x) { return modify(val - x.val); }
		modll operator*(const modll &x) { return modify(val * x.val); }
		modll operator/(const modll &x) { return modify(val * inv(x.val)); }
		modll& operator+=(const modll &x) { val = modify(val + x.val); return *this; }
		modll& operator-=(const modll &x) { val = modify(val - x.val); return *this; }
		modll& operator*=(const modll &x) { val = modify(val * x.val); return *this; }
		modll& operator/=(const modll &x) { val = modify(val * inv(x.val)); return *this; }
		bool operator==(const modll &x) { return val == x.val; }
		bool operator!=(const modll &x) { return val != x.val; }
		friend istream& operator >> (istream &is, modll& x) { is >> x.val; return is; }
		friend ostream& operator << (ostream &os, const modll& x) { os << x.val; return os; }
		ll get_val() { return val; }
	};

	modll pow(modll n, ll p) {
		modll ret;
		if (p == 0) ret = 1;
		else if (p == 1) ret = n;
		else {
			ret = pow(n, p / 2);
			ret *= ret;
			if (p % 2 == 1) ret *= n;
		}
		return ret;
	}

	vector<modll> facts;

	void make_facts(int n) {
		if (facts.empty()) facts.push_back(modll(1));
		for (int i = (int)facts.size(); i <= n; ++i) facts.push_back(modll(facts.back() * (ll)i));
		return;
	}

	vector<modll> ifacts;
	vector<modll> invs;

	void make_invs(int n) {
		if (invs.empty()) {
			invs.push_back(modll(0));
			invs.push_back(modll(1));
		}
		for (int i = (int)invs.size(); i <= n; ++i) {
			// because 0 = MOD = kq + r, 1/k = -q/r
			invs.push_back(invs[(int)MOD % i] * ((int)MOD - (int)MOD / i));
		}
		return;
	}

	void make_ifacts(int n) {
		make_invs(n);
		if (ifacts.empty()) ifacts.push_back(modll(1));
		for (int i = (int)ifacts.size(); i <= n; ++i) ifacts.push_back(modll(ifacts.back() * invs[i]));
		return;
	}

	//nCr
	modll combination(ll n, ll r) {
		if (n >= r && r >= 0) {
			modll ret;
			make_facts((int)n);
			make_ifacts((int)n);
			ret = facts[(unsigned)n] * ifacts[(unsigned)r] * ifacts[(unsigned)(n - r)];
			return ret;
		}
		else return 0;
	}

	modll get_fact(ll n) {
		make_facts((int)n);
		return facts[(int)n];
	}

	modll get_ifact(ll n) {
		make_ifacts((int)n);
		return ifacts[(int)n];
	}

	//log_a(b), if x does not exist, return -1
	ll disc_log(modll a, modll b) {
		ll ret = -1;
		ll m = ceilsqrt(MOD);
		unordered_map<ll, ll> mp;
		modll x = 1;
		Loop(i, m) {
			mp[x.get_val()] = i;
			x *= a;
		}
		x = modll(1) / pow(a, m);
		modll k = b;
		Loop(i, m) {
			if (mp.find(k.get_val()) == mp.end()) k *= x;
			else {
				ret = i * m + mp[k.get_val()];
				break;
			}
		}
		return ret;
	}
}

using namespace mod_op;
using vmodll = vector<modll>;
using vvmodll = vector<vmodll>;
using vvvmodll = vector<vvmodll>;

int main() {
	cin >> n;
	lst.resize(n);
	cnt.resize(n);
	from = vi(n, INT_MIN);
	Loop(i, n - 1) {
		int s, t; cin >> s >> t; s--; t--;
		lst[s].push_back(t);
		lst[t].push_back(s);
	}
	from[0] = -1;
	count(0, 1);
	//
	modll ans = 0;
	Loop(i, n) {
		ans += get_fact(n) / cnt[i];
	}
	cout << ans << endl;
}
0