結果

問題 No.1103 Directed Length Sum
ユーザー ゆにぽけゆにぽけ
提出日時 2023-10-09 11:54:22
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 664 ms / 3,000 ms
コード長 2,981 bytes
コンパイル時間 1,331 ms
コンパイル使用メモリ 128,552 KB
実行使用メモリ 149,492 KB
最終ジャッジ日時 2024-07-26 18:26:23
合計ジャッジ時間 8,485 ms
ジャッジサーバーID
(参考情報)
judge1 / judge3
このコードへのチャレンジ
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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 13 ms
34,432 KB
testcase_01 AC 13 ms
34,724 KB
testcase_02 AC 359 ms
149,492 KB
testcase_03 AC 179 ms
44,008 KB
testcase_04 AC 357 ms
48,784 KB
testcase_05 AC 664 ms
55,776 KB
testcase_06 AC 222 ms
42,156 KB
testcase_07 AC 46 ms
36,324 KB
testcase_08 AC 70 ms
37,540 KB
testcase_09 AC 33 ms
35,992 KB
testcase_10 AC 105 ms
38,684 KB
testcase_11 AC 397 ms
49,260 KB
testcase_12 AC 225 ms
44,284 KB
testcase_13 AC 108 ms
38,352 KB
testcase_14 AC 28 ms
35,072 KB
testcase_15 AC 174 ms
40,432 KB
testcase_16 AC 457 ms
50,036 KB
testcase_17 AC 470 ms
51,284 KB
testcase_18 AC 102 ms
38,228 KB
testcase_19 AC 410 ms
49,012 KB
testcase_20 AC 37 ms
35,628 KB
testcase_21 AC 61 ms
37,616 KB
testcase_22 AC 321 ms
47,448 KB
testcase_23 AC 179 ms
41,168 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<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#include<cassert>
#include<cmath>
#include<ctime>
#include<iomanip>
#include<numeric>
#include<stack>
#include<queue>
#include<map>
#include<unordered_map>
#include<set>
#include<unordered_set>
#include<bitset>
#include<random>
using namespace std;
template<int m> struct modint
{
	private:
	unsigned int value;
	static constexpr int mod() {return m;}

	public:
	constexpr modint(const long long x = 0) noexcept
	{
		long long y = x;
		if(y < 0 || y >= mod())
		{
			y %= mod();
			if(y < 0) y += mod();
		}
		value = (unsigned int)y;
	}
	constexpr unsigned int val() noexcept {return value;}
	constexpr modint &operator+=(const modint &other) noexcept
	{
		value += other.value;
		if(value >= mod()) value -= mod();
		return *this;
	}
	constexpr modint &operator-=(const modint &other) noexcept
	{
		unsigned int x = value;
		if(x < other.value) x += mod();
		x -= other.value;
		value = x;
		return *this;
	}
	constexpr modint &operator*=(const modint &other) noexcept
	{
		unsigned long long x = value;
		x *= other.value;
		value = (unsigned int) (x % mod());
		return *this;
	}
	constexpr modint &operator/=(const modint &other) noexcept
	{
		return *this *= other.inverse();
	}
	constexpr modint inverse() const noexcept
	{
		assert(value);
		long long a = value,b = mod(),x = 1,y = 0;
		while(b)
		{
			long long q = a/b;
			a -= q*b; swap(a,b);
			x -= q*y; swap(x,y);
		}
		return modint(x);
	}
	constexpr modint power(long long N) const noexcept
	{
		assert(N >= 0);
		modint p = *this,ret = 1;
		while(N)
		{
			if(N & 1) ret *= p;
			p *= p;
			N >>= 1;
		}
		return ret;
	}
	constexpr modint operator+() {return *this;}
	constexpr modint operator-() {return modint() - *this;}
	constexpr modint &operator++(int) noexcept {return *this += 1;}
	constexpr modint &operator--(int) noexcept {return *this -= 1;}
	friend modint operator+(const modint& lhs, const modint& rhs) {return modint(lhs) += rhs;}
	friend modint operator-(const modint& lhs, const modint& rhs) {return modint(lhs) -= rhs;}
	friend modint operator*(const modint& lhs, const modint& rhs) {return modint(lhs) *= rhs;}
	friend modint operator/(const modint& lhs, const modint& rhs) {return modint(lhs) /= rhs;}
	friend ostream &operator<<(ostream &os,const modint &x) {return os << x.value;}
};
//using mint = modint<998244353>;
using mint = modint<1000000007>;
int N,deg[1 << 20],ch[1 << 20];
vector<int> G[1 << 20];
mint D[1 << 20];

void dfs(int u)
{
	ch[u] = 1;
	for(int v:G[u])
	{
		dfs(v);
		ch[u] += ch[v];
		D[u] += D[v]+ch[v];
	}
}
void solve()
{
	cin >> N;
	for(int i = 1;i < N;i++)
	{
		int u,v;
		cin >> u >> v;
		u--; v--;
		G[u].push_back(v);
		deg[v]++;
	}
	int r = -1;
	for(int i = 0;i < N;i++) if(!deg[i]) r = i;
	dfs(r);
	mint ans = 0;
	for(int i = 0;i < N;i++) ans += D[i];
	cout << ans << endl;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int tt = 1;
	//cin >> tt;
	while(tt--) solve();
}
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