結果

問題 No.1507 Road Blocked
ユーザー suta28407928suta28407928
提出日時 2021-05-14 22:24:01
言語 C++14
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 119 ms / 2,000 ms
コード長 4,899 bytes
コンパイル時間 2,669 ms
コンパイル使用メモリ 190,200 KB
実行使用メモリ 15,488 KB
最終ジャッジ日時 2024-11-15 01:04:18
合計ジャッジ時間 7,661 ms
ジャッジサーバーID
(参考情報)
judge4 / judge5
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 2 ms
6,816 KB
testcase_01 AC 2 ms
6,820 KB
testcase_02 AC 2 ms
6,820 KB
testcase_03 AC 77 ms
15,488 KB
testcase_04 AC 118 ms
9,984 KB
testcase_05 AC 112 ms
9,984 KB
testcase_06 AC 113 ms
9,936 KB
testcase_07 AC 117 ms
9,984 KB
testcase_08 AC 117 ms
9,984 KB
testcase_09 AC 110 ms
9,984 KB
testcase_10 AC 114 ms
9,984 KB
testcase_11 AC 115 ms
9,980 KB
testcase_12 AC 115 ms
10,048 KB
testcase_13 AC 114 ms
9,856 KB
testcase_14 AC 113 ms
9,984 KB
testcase_15 AC 115 ms
10,112 KB
testcase_16 AC 119 ms
10,112 KB
testcase_17 AC 116 ms
9,984 KB
testcase_18 AC 115 ms
9,984 KB
testcase_19 AC 115 ms
9,984 KB
testcase_20 AC 114 ms
9,976 KB
testcase_21 AC 116 ms
9,984 KB
testcase_22 AC 116 ms
10,112 KB
testcase_23 AC 112 ms
9,984 KB
testcase_24 AC 114 ms
10,112 KB
testcase_25 AC 115 ms
9,984 KB
testcase_26 AC 111 ms
10,000 KB
testcase_27 AC 112 ms
9,984 KB
testcase_28 AC 109 ms
10,076 KB
testcase_29 AC 110 ms
9,984 KB
testcase_30 AC 115 ms
9,984 KB
testcase_31 AC 113 ms
10,112 KB
testcase_32 AC 109 ms
9,984 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 #

#pragma GCC target("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
#define DEBUG
#ifdef DEBUG
template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    os << '(' << p.first << ',' << p.second << ')';
    return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
    os << '{';
    for(int i = 0; i < (int)v.size(); i++) {
        if(i) { os << ','; }
        os << v[i];
    }
    os << '}';
    return os;
}
void debugg() { cerr << endl; }
template <class T, class... Args>
void debugg(const T &x, const Args &... args) {
    cerr << " " << x;
    debugg(args...);
}
#define debug(...)                                                             \
    cerr << __LINE__ << " [" << #__VA_ARGS__ << "]: ", debugg(__VA_ARGS__)
#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef pair<ll,ll> P;
typedef pair<int,int> pii;
typedef vector<P> vpl;
typedef tuple<ll,ll,ll> tapu;
#define rep(i,n) for(int i=0; i<(n); i++)
#define REP(i,a,b) for(int i=(a); i<(b); i++)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const int inf = (1<<30)-1;
const ll linf = 1LL<<61;
const int MAX = 510000;
int dy[8] = {0,1,0,-1,1,-1,-1,1};
int dx[8] = {-1,0,1,0,1,-1,1,-1};
const double pi = acos(-1);
const double eps = 1e-9;
template<typename T1,typename T2> inline bool chmin(T1 &a,T2 b){
	if(a>b){
		a = b; return true;
	}
	else return false;
}
template<typename T1,typename T2> inline bool chmax(T1 &a,T2 b){
	if(a<b){
		a = b; return true;
	}
	else return false;
}
template<typename T> inline void print(T &a){
    int sz = a.size();
    for(auto itr = a.begin(); itr != a.end(); itr++){
		cout << *itr;
        sz--;
        if(sz) cout << " ";
	}
    cout << "\n";
}
template<typename T1,typename T2> inline void print2(T1 a, T2 b){
	cout << a << " " << b << "\n";
}
template<typename T1,typename T2,typename T3> inline void print3(T1 a, T2 b, T3 c){
	cout << a << " " << b << " " << c << "\n";
}
void mark() {cout << "#" << "\n";}
ll pcount(ll x) {return __builtin_popcountll(x);}
//const int mod = 1e9 + 7;
const int mod = 998244353;

template <int mod> struct ModInt {
    int x;

    ModInt() : x(0) {}

    ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

    ModInt &operator+=(const ModInt &p) {
        if((x += p.x) >= mod) x -= mod;
        return *this;
    }

    ModInt &operator-=(const ModInt &p) {
        if((x += mod - p.x) >= mod) x -= mod;
        return *this;
    }

    ModInt &operator*=(const ModInt &p) {
        x = (int)(1LL * x * p.x % mod);
        return *this;
    }

    ModInt &operator/=(const ModInt &p) {
        *this *= p.inverse();
        return *this;
    }

    ModInt operator-() const { return ModInt(-x); }

    ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }

    ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }

    ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }

    ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }

    bool operator==(const ModInt &p) const { return x == p.x; }

    bool operator!=(const ModInt &p) const { return x != p.x; }

    ModInt inverse() const {
        int a = x, b = mod, u = 1, v = 0, t;
        while(b > 0) {
            t = a / b;
            swap(a -= t * b, b);
            swap(u -= t * v, v);
        }
        return ModInt(u);
    }

    ModInt pow(int64_t n) const {
        ModInt ret(1), mul(x);
        while(n > 0) {
            if(n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }

    friend ostream &operator<<(ostream &os, const ModInt &p) {
        return os << p.x;
    }

    friend istream &operator>>(istream &is, ModInt &a) {
        int64_t t;
        is >> t;
        a = ModInt<mod>(t);
        return (is);
    }

    static int get_mod() { return mod; }
};

using mint = ModInt<mod>;

int main(){
    ll n; cin >> n;
    vvl G(n);
    rep(i,n-1){
        int u,v; cin >> u >> v; u--; v--;
        G[v].push_back(u);
        G[u].push_back(v);
    }
    mint ans = n*(n-1)/2*(n-1) % mod;
    vl c(n,1);
    auto dfs = [&](auto &&dfs, int u, int p) -> void {
        for(auto v : G[u]){
            if(v == p) continue;
            dfs(dfs,v,u);
            c[u] += c[v];
            ans -= c[v] * (n - c[v]);
            //debug(v,c[v]*(n-c[v]));
        }
    };
    dfs(dfs,0,-1);
    ans /= n*(n-1)/2*(n-1);
    cout << ans << endl;
}
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