結果

問題 No.1124 Earthquake Safety
ユーザー yosupotyosupot
提出日時 2020-07-22 22:47:18
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 196 ms / 3,000 ms
コード長 7,710 bytes
コンパイル時間 1,400 ms
コンパイル使用メモリ 123,820 KB
実行使用メモリ 42,936 KB
最終ジャッジ日時 2024-06-22 23:41:27
合計ジャッジ時間 9,586 ms
ジャッジサーバーID
（参考情報） 		judge2 / 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 2 ms
5,248 KB
testcase_01 AC 2 ms
5,376 KB
testcase_02 AC 2 ms
5,376 KB
testcase_03 AC 2 ms
5,376 KB
testcase_04 AC 2 ms
5,376 KB
testcase_05 AC 2 ms
5,376 KB
testcase_06 AC 2 ms
5,376 KB
testcase_07 AC 4 ms
5,376 KB
testcase_08 AC 38 ms
8,576 KB
testcase_09 AC 124 ms
19,908 KB
testcase_10 AC 73 ms
42,936 KB
testcase_11 AC 2 ms
5,376 KB
testcase_12 AC 2 ms
5,376 KB
testcase_13 AC 2 ms
5,376 KB
testcase_14 AC 130 ms
19,812 KB
testcase_15 AC 152 ms
19,792 KB
testcase_16 AC 146 ms
19,792 KB
testcase_17 AC 196 ms
19,840 KB
testcase_18 AC 118 ms
19,932 KB
testcase_19 AC 128 ms
19,836 KB
testcase_20 AC 130 ms
19,840 KB
testcase_21 AC 138 ms
19,712 KB
testcase_22 AC 127 ms
19,712 KB
testcase_23 AC 112 ms
19,636 KB
testcase_24 AC 120 ms
19,584 KB
testcase_25 AC 134 ms
19,828 KB
testcase_26 AC 129 ms
19,712 KB
testcase_27 AC 127 ms
21,120 KB
testcase_28 AC 115 ms
21,060 KB
testcase_29 AC 125 ms
25,216 KB
testcase_30 AC 110 ms
24,960 KB
testcase_31 AC 126 ms
33,920 KB
testcase_32 AC 129 ms
32,316 KB
testcase_33 AC 131 ms
31,672 KB
testcase_34 AC 140 ms
33,664 KB
testcase_35 AC 130 ms
19,580 KB
testcase_36 AC 106 ms
19,496 KB
testcase_37 AC 114 ms
20,688 KB
testcase_38 AC 108 ms
20,476 KB
testcase_39 AC 129 ms
20,224 KB
testcase_40 AC 102 ms
20,972 KB
testcase_41 AC 104 ms
20,288 KB
testcase_42 AC 112 ms
20,992 KB
testcase_43 AC 104 ms
21,156 KB
testcase_44 AC 121 ms
21,096 KB
testcase_45 AC 116 ms
20,736 KB
testcase_46 AC 115 ms
21,044 KB
testcase_47 AC 122 ms
20,736 KB
testcase_48 AC 91 ms
20,728 KB
testcase_49 AC 104 ms
20,716 KB
testcase_50 AC 1 ms
5,376 KB
testcase_51 AC 2 ms
5,376 KB
testcase_52 AC 1 ms
5,376 KB
testcase_53 AC 2 ms
5,376 KB
testcase_54 AC 2 ms
5,376 KB
testcase_55 AC 1 ms
5,376 KB
testcase_56 AC 2 ms
5,376 KB
testcase_57 AC 2 ms
5,376 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 optimize("Ofast")
//#pragma GCC target("avx")
//#undef LOCAL




#include <algorithm>

#include <array>

#include <bitset>

#include <cassert>

#include <complex>

#include <cstdio>

#include <cstring>

#include <iostream>

#include <map>

#include <numeric>

#include <queue>

#include <set>

#include <string>

#include <unordered_map>

#include <unordered_set>

#include <vector>

using namespace std;

using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n - 1); }
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;



#include <unistd.h>

struct Scanner {
    int fd = -1;
    char line[(1 << 15) + 1];
    size_t st = 0, ed = 0;
    void reread() {
        memmove(line, line + st, ed - st);
        ed -= st;
        st = 0;
        ed += ::read(fd, line + ed, (1 << 15) - ed);
        line[ed] = '\0';
    }
    bool succ() {
        while (true) {
            if (st == ed) {
                reread();
                if (st == ed) return false;
            }
            while (st != ed && isspace(line[st])) st++;
            if (st != ed) break;
        }
        if (ed - st <= 50) {
            bool sep = false;
            for (size_t i = st; i < ed; i++) {
                if (isspace(line[i])) {
                    sep = true;
                    break;
                }
            }
            if (!sep) reread();
        }
        return true;
    }
    template <class T, enable_if_t<is_same<T, string>::value, int> = 0>
    bool read_single(T& ref) {
        if (!succ()) return false;
        while (true) {
            size_t sz = 0;
            while (st + sz < ed && !isspace(line[st + sz])) sz++;
            ref.append(line + st, sz);
            st += sz;
            if (!sz || st != ed) break;
            reread();
        }
        return true;
    }
    template <class T, enable_if_t<is_integral<T>::value>* = nullptr>
    bool read_single(T& ref) {
        if (!succ()) return false;
        bool neg = false;
        if (line[st] == '-') {
            neg = true;
            st++;
        }
        ref = T(0);
        while (isdigit(line[st])) {
            ref = 10 * ref + (line[st++] & 0xf);
        }
        if (neg) ref = -ref;
        return true;
    }
    template <class T> bool read_single(V<T>& ref) {
        for (auto& d : ref) {
            if (!read_single(d)) return false;
        }
        return true;
    }
    void read() {}
    template <class H, class... T> void read(H& h, T&... t) {
        bool f = read_single(h);
        assert(f);
        read(t...);
    }
    int read_unsafe() { return 0; }
    template <class H, class... T> int read_unsafe(H& h, T&... t) {
        bool f = read_single(h);
        if (!f) return 0;
        return 1 + read_unsafe(t...);
    }
    Scanner(FILE* fp) : fd(fileno(fp)) {}
};

struct Printer {
  public:
    template <bool F = false> void write() {}
    template <bool F = false, class H, class... T>
    void write(const H& h, const T&... t) {
        if (F) write_single(' ');
        write_single(h);
        write<true>(t...);
    }
    template <class... T> void writeln(const T&... t) {
        write(t...);
        write_single('\n');
    }

    Printer(FILE* _fp) : fp(_fp) {}
    ~Printer() { flush(); }

  private:
    static constexpr size_t SIZE = 1 << 15;
    FILE* fp;
    char line[SIZE], small[50];
    size_t pos = 0;
    void flush() {
        fwrite(line, 1, pos, fp);
        pos = 0;
    }
    void write_single(const char& val) {
        if (pos == SIZE) flush();
        line[pos++] = val;
    }
    template <class T, enable_if_t<is_integral<T>::value>* = nullptr>
    void write_single(T val) {
        if (pos > (1 << 15) - 50) flush();
        if (val == 0) {
            write_single('0');
            return;
        }
        if (val < 0) {
            write_single('-');
            val = -val; // todo min
        }
        size_t len = 0;
        while (val) {
            small[len++] = char(0x30 | (val % 10));
            val /= 10;
        }
        for (size_t i = 0; i < len; i++) {
            line[pos + i] = small[len - 1 - i];
        }
        pos += len;
    }
    void write_single(__int128 val) {
        if (pos > (1 << 15) - 50) flush();
        if (val == 0) {
            write_single('0');
            return;
        }
        if (val < 0) {
            write_single('-');
            val = -val; // todo min
        }
        size_t len = 0;
        while (val) {
            small[len++] = char(0x30 | (val % 10));
            val /= 10;
        }
        for (size_t i = 0; i < len; i++) {
            line[pos + i] = small[len - 1 - i];
        }
        pos += len;
    }

    void write_single(const string& s) {
        for (char c : s) write_single(c);
    }
    void write_single(const char* s) {
        size_t len = strlen(s);
        for (size_t i = 0; i < len; i++) write_single(s[i]);
    }
    template <class T> void write_single(const V<T>& val) {
        auto n = val.size();
        for (size_t i = 0; i < n; i++) {
            if (i) write_single(' ');
            write_single(val[i]);
        }
    }
};


template <uint MD> struct ModInt {
    using M = ModInt;
    static constexpr uint get_mod() { return MD; }
    const static M G;
    uint v;
    ModInt(ll _v = 0) { set_v(uint(_v % MD + MD)); }
    M& set_v(uint _v) {
        v = (_v < MD) ? _v : _v - MD;
        return *this;
    }
    explicit operator bool() const { return v != 0; }
    M operator-() const { return M() - *this; }
    M operator+(const M& r) const { return M().set_v(v + r.v); }
    M operator-(const M& r) const { return M().set_v(v + MD - r.v); }
    M operator*(const M& r) const { return M().set_v(uint(ull(v) * r.v % MD)); }
    M operator/(const M& r) const { return *this * r.inv(); }
    M& operator+=(const M& r) { return *this = *this + r; }
    M& operator-=(const M& r) { return *this = *this - r; }
    M& operator*=(const M& r) { return *this = *this * r; }
    M& operator/=(const M& r) { return *this = *this / r; }
    bool operator==(const M& r) const { return v == r.v; }
    M pow(ll n) const {
        M x = *this, r = 1;
        while (n) {
            if (n & 1) r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    M inv() const { return pow(MD - 2); }
    friend ostream& operator<<(ostream& os, const M& r) { return os << r.v; }
};
// using Mint = ModInt<998244353>;
// template<> const Mint Mint::G = Mint(3);
using Mint = ModInt<TEN(9) + 7>;

Mint i2 = Mint(2).inv();

Scanner sc = Scanner(stdin);
Printer pr = Printer(stdout);

struct DP {
    Mint d0, d1, d2, dsm;
};

VV<int> g;

DP solve(int p, int b) {
    DP dp = {1, 0, 0, 0};
    for (int d: g[p]) {
        if (d == b) continue;
        DP cdp = solve(d, p);

        DP ndp = {
            1,
            dp.d0 * cdp.d1 + dp.d1 * cdp.d0,
            dp.d0 * cdp.d2 + dp.d1 * cdp.d1 * Mint(2) + dp.d2 * cdp.d0,
            dp.dsm + cdp.dsm + dp.d1 * cdp.d2 * Mint(3) + dp.d2 * cdp.d1 * Mint(3),
        };

        dp = ndp;
    }

    DP ndp = {
        1,
        (dp.d1 + dp.d0) * i2,
        (dp.d2 + dp.d1 * Mint(2) + dp.d0) * i2,
        dp.dsm + dp.d2 * Mint(3) + dp.d1 * Mint(3) + dp.d0,
    };
    //dbg(ndp.d0, ndp.d1, ndp.d2, ndp.dsm, ndp.dsm * Mint(2).pow(2));

    return ndp;
}

int main() {
    int n;
    sc.read(n);
    g = VV<int>(n);
    for (int i = 0; i < n - 1; i++) {
        int a, b;
        sc.read(a, b); a--; b--;
        g[a].push_back({b});
        g[b].push_back({a});
    }

    auto ans = solve(0, -1);
    pr.writeln((ans.dsm * Mint(2).pow(n - 1)).v);
    return 0;
}
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