結果

問題 No.1103 Directed Length Sum
ユーザー micheeeeell1001micheeeeell1001
提出日時 2020-07-03 23:10:43
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 659 ms / 3,000 ms
コード長 6,056 bytes
コンパイル時間 2,244 ms
コンパイル使用メモリ 211,012 KB
実行使用メモリ 159,440 KB
最終ジャッジ日時 2024-09-17 04:50:06
合計ジャッジ時間 8,868 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge5
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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
6,812 KB
testcase_01 AC 2 ms
6,944 KB
testcase_02 AC 338 ms
159,440 KB
testcase_03 AC 175 ms
59,624 KB
testcase_04 AC 347 ms
40,120 KB
testcase_05 AC 659 ms
67,164 KB
testcase_06 AC 221 ms
27,296 KB
testcase_07 AC 39 ms
8,960 KB
testcase_08 AC 66 ms
12,020 KB
testcase_09 AC 23 ms
6,940 KB
testcase_10 AC 100 ms
15,324 KB
testcase_11 AC 396 ms
43,432 KB
testcase_12 AC 227 ms
27,436 KB
testcase_13 AC 100 ms
15,656 KB
testcase_14 AC 17 ms
6,944 KB
testcase_15 AC 183 ms
22,088 KB
testcase_16 AC 443 ms
48,468 KB
testcase_17 AC 469 ms
50,400 KB
testcase_18 AC 102 ms
15,124 KB
testcase_19 AC 403 ms
44,436 KB
testcase_20 AC 26 ms
7,552 KB
testcase_21 AC 54 ms
11,136 KB
testcase_22 AC 311 ms
36,896 KB
testcase_23 AC 186 ms
23,404 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 # 

#ifdef LOCAL
#define _GLIBCXX_DEBUG
#endif
#include<bits/stdc++.h>
using namespace std;
#define rep(i,s,t) for(ll i = (ll)(s); i < (ll)(t); i++)
#define rrep(i,s,t) for(ll i = (ll)(s-1);(ll)(t) <= i; i--)
#define all(x) (x).begin(), (x).end()
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> Pll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
constexpr ll INF = numeric_limits<ll>::max()/4;
constexpr ll n_max = 2e5+10;
#define int ll

template <typename A, typename B>
string to_string(pair<A, B> p);
string to_string(const string &s) {return '"' + s + '"';}
string to_string(const char *c) {return to_string((string) c);}
string to_string(bool b) {return (b ? "true" : "false");}
template <size_t N>
string to_string(bitset<N> v){
    string res = "";
    for(size_t i = 0; i < N; i++) res += static_cast<char>('0' + v[i]);
    return res;
}
template <typename A>
string to_string(A v) {
    bool first = true;
    string res = "{";
    for(const auto &x : v) {
        if(!first) res += ", ";
        first = false;
        res += to_string(x);
    }
    res += "}";
    return res;
}
template <typename A, typename B>
string to_string(pair<A, B> p){return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";}

void debug_out() {cerr << endl;}
template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << " " << to_string(H);
    debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

template<class T>
bool chmax(T &a, T b){if(a < b){a = b; return true;} return false;}
template<class T>
bool chmin(T &a, T b){if(a > b){a = b; return true;} return false;}

template<std::int_fast64_t Modulus>
class modint {
    using i64 = int_fast64_t;

    public:
    i64 a;

    constexpr modint(const i64 x = 0) noexcept {
        this -> a = x % Modulus;
        if(a < 0){
            a += Modulus;
        }
    }
    constexpr int getmod() { return Modulus; }
    constexpr modint operator - () const noexcept {
        return a ? Modulus - a : 0;
    }
    constexpr const i64 &value() const noexcept {return a;}
    constexpr modint operator+(const modint rhs) const noexcept {
        return modint(*this) += rhs;
    }
    constexpr modint operator-(const modint rhs) const noexcept {
        return modint(*this) -= rhs;
    }
    constexpr modint operator*(const modint rhs) const noexcept {
        return modint(*this) *= rhs;
    }
    constexpr modint operator/(const modint rhs) const noexcept {
        return modint(*this) /= rhs;
    }
    constexpr modint &operator+=(const modint rhs) noexcept {
        a += rhs.a;
        if(a >= Modulus) {
            a -= Modulus;
        }
        return *this;
    }
    constexpr modint &operator-=(const modint rhs) noexcept {
        if(a < rhs.a) {
            a += Modulus;
        }
        a -= rhs.a;
        return *this;
    }
    constexpr modint &operator*=(const modint rhs) noexcept {
        a = a * rhs.a % Modulus;
        return *this;
    }
    constexpr modint &operator/=(modint rhs) noexcept {
        i64 a_ = rhs.a, b = Modulus, u = 1, v = 0;
        while(b){
            i64 t = a_/b;
            a_ -= t * b; swap(a_,b);
            u -= t * v; swap(u,v);
        }
        a = a * u % Modulus;
        if(a < 0) a += Modulus;
        return *this;
    }
    
    // 自前実装
    constexpr bool operator==(const modint rhs) noexcept {
        return a == rhs.a;
    }
    constexpr bool operator!=(const modint rhs) noexcept {
        return a != rhs.a;
    }
    constexpr bool operator>(const modint rhs) noexcept {
        return a > rhs.a;
    }
    constexpr bool operator>=(const modint rhs) noexcept {
        return a >= rhs.a;
    }
    constexpr bool operator<(const modint rhs) noexcept {
        return a < rhs.a;
    }
    constexpr bool operator<=(const modint rhs) noexcept {
        return a <= rhs.a;
    }
    constexpr modint& operator++() noexcept {
        return (*this) += modint(1);
    }
    // constexpr modint operator++(int) {
    //     modint tmp(*this);
    //     operator++();
    //     return tmp;
    // }
    constexpr modint& operator--() noexcept {
        return (*this) -= modint(1);
    }
    // constexpr modint operator--(int) {
    //     modint tmp(*this);
    //     operator--();
    //     return tmp;
    // }
    template<typename T>
    friend constexpr modint modpow(const modint &mt, T n) noexcept {
        if(n < 0){
            modint t = (modint(1) / mt);
            return modpow(t, -n);
        }
        modint res = 1, tmp = mt;
        while(n){
            if(n & 1)res *= tmp;
            tmp *= tmp;
            n /= 2;
        }
        return res;
    }

    friend constexpr string to_string(const modint &mt) noexcept {
        return to_string(mt.a);
    }
};

// 標準入出力対応
template<std::int_fast64_t Modulus>
std::ostream &operator<<(std::ostream &out, const modint<Modulus> &m) {
    out << m.a;
    return out;
}
template<std::int_fast64_t Modulus>
std::istream &operator>>(std::istream &in, modint<Modulus> &m) {
    ll a;
    in >> a;
    m = modint<Modulus>(a);
    return in;
}

const ll MOD = 1e9+7;
// const ll MOD = 998244353;
using mint = modint<MOD>;

vector<vector<ll>> graph;
vector<mint> sub,cnt;
void dfs(ll now){
    mint c = 0;
    for(auto &to : graph[now]){
        dfs(to);
        sub[now] += sub[to];
        sub[now] += cnt[to];
        cnt[now] += cnt[to] + 1;
        c += 1;
    }
    sub[now] += c;
}


signed main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    ll n; cin >> n;
    graph.resize(n);
    sub.resize(n);cnt.resize(n);

    vector<ll> in(n);
    rep(i,0,n-1){
        ll a,b; cin >> a >> b;
        a--;b--;
        graph[a].emplace_back(b);
        in[b]++;
    }
    ll root = 0;
    rep(i,0,n) if(!in[i]){
        root = i;
        break;
    }
    dfs(root);
    debug(sub, cnt);
    mint ans = 0;
    rep(i,0,n)ans += sub[i];
    cout << ans << "\n";
}
0