結果

問題 No.1333 Squared Sum
ユーザー mtsdmtsd
提出日時 2021-01-08 23:51:36
言語 C++14
(gcc 13.2.0 + boost 1.83.0)
結果
AC  
実行時間 359 ms / 2,000 ms
コード長 6,329 bytes
コンパイル時間 1,542 ms
コンパイル使用メモリ 125,828 KB
実行使用メモリ 44,420 KB
最終ジャッジ日時 2023-08-10 12:49:08
合計ジャッジ時間 12,204 ms
ジャッジサーバーID
（参考情報） 		judge15 / judge13
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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 3 ms
5,804 KB
testcase_01 AC 3 ms
5,720 KB
testcase_02 AC 3 ms
5,764 KB
testcase_03 AC 321 ms
20,768 KB
testcase_04 AC 318 ms
20,404 KB
testcase_05 AC 323 ms
20,368 KB
testcase_06 AC 316 ms
20,548 KB
testcase_07 AC 317 ms
20,356 KB
testcase_08 AC 320 ms
20,380 KB
testcase_09 AC 314 ms
20,392 KB
testcase_10 AC 316 ms
20,568 KB
testcase_11 AC 318 ms
20,700 KB
testcase_12 AC 320 ms
20,384 KB
testcase_13 AC 322 ms
44,392 KB
testcase_14 AC 354 ms
32,028 KB
testcase_15 AC 359 ms
41,436 KB
testcase_16 AC 3 ms
5,744 KB
testcase_17 AC 4 ms
5,744 KB
testcase_18 AC 3 ms
5,760 KB
testcase_19 AC 3 ms
5,896 KB
testcase_20 AC 3 ms
5,664 KB
testcase_21 AC 3 ms
5,660 KB
testcase_22 AC 3 ms
5,752 KB
testcase_23 AC 3 ms
5,680 KB
testcase_24 AC 3 ms
5,660 KB
testcase_25 AC 3 ms
5,700 KB
testcase_26 AC 357 ms
43,868 KB
testcase_27 AC 345 ms
32,764 KB
testcase_28 AC 355 ms
43,620 KB
testcase_29 AC 317 ms
44,420 KB
testcase_30 AC 117 ms
11,712 KB
testcase_31 AC 63 ms
9,092 KB
testcase_32 AC 181 ms
14,364 KB
testcase_33 AC 140 ms
12,568 KB
testcase_34 AC 252 ms
17,460 KB
testcase_35 AC 182 ms
14,736 KB
testcase_36 AC 102 ms
10,940 KB
testcase_37 AC 107 ms
11,236 KB
testcase_38 AC 128 ms
12,068 KB
testcase_39 AC 211 ms
15,880 KB
testcase_40 AC 255 ms
21,000 KB
testcase_41 AC 250 ms
21,020 KB
testcase_42 AC 255 ms
21,056 KB
testcase_43 AC 229 ms
21,064 KB
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ソースコード

diff # 

#include <algorithm>
#include <bitset>
#include <cassert>
#include <chrono>
#include <climits>
#include <cmath>
#include <complex>
#include <cstring>
#include <deque>
#include <functional>
#include <iostream>
#include <iomanip>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <cstdint>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pii;
#define MP make_pair
#define PB push_back
#define inf 1000000007
#define rep(i,n) for(int i = 0; i < (int)(n); ++i)
#define all(x) (x).begin(),(x).end()

template<typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val){
    std::fill( (T*)array, (T*)(array+N), val );
}
 
template<class T> inline bool chmax(T &a, T b){
    if(a<b){
        a = b;
        return true;
    }
    return false;
}

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


template <unsigned int mod>
class ModInt {
private:
    unsigned int v;
    static unsigned int norm(const unsigned int& x){ return x < mod ? x : x - mod; }
    static ModInt make(const unsigned int& x){ ModInt m; return m.v = x, m; }
    static ModInt inv(const ModInt& x){ return make(inverse(x.v, mod)); }
    static unsigned int inverse(int a, int m){
        int u[] = {a, 1, 0}, v[] = {m, 0, 1}, t;
        while(*v){
            t = *u / *v;
            swap(u[0] -= t * v[0], v[0]), swap(u[1] -= t * v[1], v[1]), swap(u[2] -= t * v[2], v[2]);
        }
        return (u[1] % m + m) % m;
    }

public:
    ModInt() : v{0}{}
    ModInt(const long long val) : v{norm(val % mod + mod)} {}
    ModInt(const ModInt<mod>& n) : v{n()} {}
    explicit operator bool() const noexcept { return v != 0; }
    bool operator!() const noexcept { return !static_cast<bool>(*this); }
    ModInt& operator=(const ModInt& n){ return v = n(), (*this); }
    ModInt& operator=(const long long val){ return v = norm(val % mod + mod), (*this); }
    ModInt operator+() const { return *this; }
    ModInt operator-() const { return v == 0 ? make(0) : make(mod - v); }
    ModInt operator+(const ModInt& val) const { return make(norm(v + val())); }
    ModInt operator-(const ModInt& val) const { return make(norm(v + mod - val())); }
    ModInt operator*(const ModInt& val) const { return make((long long)v * val() % mod); }
    ModInt operator/(const ModInt& val) const { return *this * inv(val); }
    ModInt& operator+=(const ModInt& val){ return *this = *this + val; }
    ModInt& operator-=(const ModInt& val){ return *this = *this - val; }
    ModInt& operator*=(const ModInt& val){ return *this = *this * val; }
    ModInt& operator/=(const ModInt& val){ return *this = *this / val; }
    ModInt operator+(const long long val) const { return ModInt{v + val}; }
    ModInt operator-(const long long val) const { return ModInt{v - val}; }
    ModInt operator*(const long long val) const { return ModInt{(long long)v * (val % mod)}; }
    ModInt operator/(const long long val) const { return ModInt{(long long)v * inv(val)}; }
    ModInt& operator+=(const long long val){ return *this = *this + val; }
    ModInt& operator-=(const long long val){ return *this = *this - val; }
    ModInt& operator*=(const long long val){ return *this = *this * val; }
    ModInt& operator/=(const long long val){ return *this = *this / val; }
    bool operator==(const ModInt& val) const { return v == val.v; }
    bool operator!=(const ModInt& val) const { return !(*this == val); }
    bool operator==(const long long val) const { return v == norm(val % mod + mod); }
    bool operator!=(const long long val) const { return !(*this == val); }
    unsigned int operator()() const { return v; }
    friend ModInt operator+(const long long val, const ModInt& n) { return n + val; }
    friend ModInt operator-(const long long val, const ModInt& n) { return ModInt{val - n()}; }
    friend ModInt operator*(const long long val, const ModInt& n) { return n * val; }
    friend ModInt operator/(const long long val, const ModInt& n) { return ModInt{val} / n; }
    friend bool operator==(const long long val, const ModInt& n) { return n == val; }
    friend bool operator!=(const long long val, const ModInt& n) { return !(val == n); }
    friend istream& operator>>(istream& is, ModInt& n){
        unsigned int v;
        return is >> v, n = v, is;
    }
    friend ostream& operator<<(ostream& os, const ModInt& n){ return (os << n()); }
    friend ModInt mod_pow(ModInt x, long long n){
        ModInt ans = 1;
        while(n){
            if(n & 1) ans *= x;
            x *= x, n >>= 1;
        }
        return ans;
    }
};

#define MOD 1000000007
using mod = ModInt<MOD>;

#define MAX_N 200000
mod inv[MAX_N],fac[MAX_N],finv[MAX_N];

void make()
{
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for(int i=2;i<MAX_N;i++){
        inv[i] = MOD - inv[MOD % i] * (MOD / i);
        fac[i] = fac[i-1] * i;
        finv[i] = finv[i-1] * inv[i];
    }
}

mod comb(int a, int b)
{
    if(a<b) return 0;
    return fac[a] * finv[b] * finv[a-b];
}

vector<vector<pair<int,mod> > > g;
vector<mod> d2,d,cnt,res;
void dfs(int id,int pre){
    for(auto x:g[id]){
        if(x.first!=pre){
            dfs(x.first,id);
        }
    }
    for(auto x:g[id]){
        if(x.first==pre)continue;
        mod P = x.second;
        int nxt = x.first;
        res[id] += d[id] * (d[nxt]+P*cnt[nxt]) * 2;
        res[id] += d2[id]*cnt[nxt] + cnt[id]*(P*2*d[nxt]+cnt[nxt]*P*P+d2[nxt]);
        d2[id] += P*2*d[nxt];
        d2[id] += cnt[nxt]*P*P;
        d2[id] += d2[nxt];
        d[id] += d[nxt] + cnt[nxt]*P;
        cnt[id] += cnt[nxt];
    }
    res[id] += d2[id];
    cnt[id]+=1;
}

int main(){
    int n;
    cin >> n;
    g.resize(n);
    d.resize(n);
    d2.resize(n);
    cnt.resize(n);
    res.resize(n);
    rep(i,n-1){
        int a,b,c;
        cin >> a >> b >> c;
        a--;b--;
        g[a].push_back(MP(b,c));
        g[b].push_back(MP(a,c));
    }    
    dfs(0,-1);
    mod ans = 0;
    rep(i,n){
        ans += res[i];
        // cerr << i << ": " << d[i] << " " << d2[i] << " " << cnt[i] << " " << res[i] << endl;
    }
    cout << ans << endl;
    return 0;
}
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