結果

問題 No.1075 木の上の山
ユーザー 👑 tute7627tute7627
提出日時 2020-06-05 22:58:12
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 78 ms / 2,000 ms
コード長 6,705 bytes
コンパイル時間 2,422 ms
コンパイル使用メモリ 225,544 KB
実行使用メモリ 42,880 KB
最終ジャッジ日時 2024-05-09 22:45:38
合計ジャッジ時間 4,324 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge4
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 1 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 1 ms
5,376 KB
testcase_05 AC 2 ms
5,376 KB
testcase_06 AC 1 ms
5,376 KB
testcase_07 AC 3 ms
5,376 KB
testcase_08 AC 3 ms
5,376 KB
testcase_09 AC 3 ms
5,376 KB
testcase_10 AC 3 ms
5,376 KB
testcase_11 AC 3 ms
5,376 KB
testcase_12 AC 3 ms
5,376 KB
testcase_13 AC 3 ms
5,376 KB
testcase_14 AC 3 ms
5,376 KB
testcase_15 AC 3 ms
5,376 KB
testcase_16 AC 3 ms
5,376 KB
testcase_17 AC 78 ms
42,880 KB
testcase_18 AC 61 ms
30,976 KB
testcase_19 AC 76 ms
40,704 KB
testcase_20 AC 62 ms
31,104 KB
testcase_21 AC 68 ms
31,488 KB
testcase_22 AC 68 ms
31,488 KB
testcase_23 AC 67 ms
31,744 KB
testcase_24 AC 66 ms
31,616 KB
testcase_25 AC 64 ms
31,360 KB
testcase_26 AC 64 ms
30,976 KB
testcase_27 AC 66 ms
31,488 KB
testcase_28 AC 73 ms
35,712 KB
testcase_29 AC 64 ms
31,488 KB
testcase_30 AC 64 ms
31,104 KB
testcase_31 AC 67 ms
33,920 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 # 

//#define _GLIBCXX_DEBUG

#include<bits/stdc++.h>
using namespace std;

#define endl '\n'
#define lfs cout<<fixed<<setprecision(10)
#define ALL(a)  (a).begin(),(a).end()
#define ALLR(a)  (a).rbegin(),(a).rend()
#define spa << " " <<
#define fi first
#define se second
#define MP make_pair
#define MT make_tuple
#define PB push_back
#define EB emplace_back
#define rep(i,n,m) for(ll i = (n); i < (ll)(m); i++)
#define rrep(i,n,m) for(ll i = (ll)(m) - 1; i >= (ll)(n); i--)
using ll = long long;
using ld = long double;
const ll MOD1 = 1e9+7;
const ll MOD9 = 998244353;
const ll INF = 1e18;
using P = pair<ll, ll>;
template<typename T1, typename T2>
bool chmin(T1 &a,T2 b){if(a>b){a=b;return true;}else return false;}
template<typename T1, typename T2>
bool chmax(T1 &a,T2 b){if(a<b){a=b;return true;}else return false;}
ll median(ll a,ll b, ll c){return a+b+c-max({a,b,c})-min({a,b,c});}
void ans1(bool x){if(x) cout<<"Yes"<<endl;else cout<<"No"<<endl;}
void ans2(bool x){if(x) cout<<"YES"<<endl;else cout<<"NO"<<endl;}
void ans3(bool x){if(x) cout<<"Yay!"<<endl;else cout<<":("<<endl;}
template<typename T1,typename T2>
void ans(bool x,T1 y,T2 z){if(x)cout<<y<<endl;else cout<<z<<endl;}  
template<typename T>
void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++)
{cout<<v[i][0];for(ll j=1;j<w;j++)cout spa v[i][j];cout<<endl;}};
void debug(vector<string>&v,ll h,ll w){for(ll i=0;i<h;i++)
{for(ll j=0;j<w;j++)cout<<v[i][j];cout<<endl;}};
template<typename T>
void debug(vector<T>&v,ll n){if(n!=0)cout<<v[0];
for(ll i=1;i<n;i++)cout spa v[i];cout<<endl;};
template<typename T>
vector<vector<T>>vec(ll x, ll y, T w){
  vector<vector<T>>v(x,vector<T>(y,w));return v;}
ll gcd(ll x,ll y){ll r;while(y!=0&&(r=x%y)!=0){x=y;y=r;}return y==0?x:y;}
vector<ll>dx={1,-1,0,0,1,1,-1,-1};
vector<ll>dy={0,0,1,-1,1,-1,1,-1};
template<typename T>
vector<T> make_v(size_t a,T b){return vector<T>(a,b);}
template<typename... Ts>
auto make_v(size_t a,Ts... ts){
  return vector<decltype(make_v(ts...))>(a,make_v(ts...));
}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2>&p){
  return os << p.first << " " << p.second;
}
//mt19937 mt(chrono::steady_clock::now().time_since_epoch().count());
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 modint = ModInt< MOD1 >;modint pow(ll n, ll x){return modint(n).pow(x);}modint pow(modint n, ll x){return n.pow(x);}
//using modint=ld;
template< typename sum_t, typename key_t >
struct ReRooting {
  struct Edge {
    int to;
    key_t data;
    sum_t dp, ndp;
  };

  using F = function< sum_t(sum_t, sum_t) >;
  using G = function< sum_t(sum_t, key_t) >;

  vector< vector< Edge > > g;
  vector< sum_t > subdp, dp;
  sum_t ident;
  const F f;
  const G gg;

  ReRooting(int V, const F f, const G g, sum_t ident)
      : g(V), f(f), gg(g), ident(ident), subdp(V, ident), dp(V, ident) {}

  void add_edge(int u, int v, const key_t &d) {
    g[u].emplace_back((Edge) {v, d, ident, ident});
    g[v].emplace_back((Edge) {u, d, ident, ident});
  }

  void add_edge_bi(int u, int v, const key_t &d, const key_t &e) {
    g[u].emplace_back((Edge) {v, d, ident, ident});
    g[v].emplace_back((Edge) {u, e, ident, ident});
  }

  void dfs_sub(int idx, int par) {
    for(auto &e : g[idx]) {
      if(e.to == par) continue;
      dfs_sub(e.to, idx);
      subdp[idx] = f(subdp[idx], gg(subdp[e.to], e.data));
    }
  }

  void dfs_all(int idx, int par, const sum_t &top) {
    sum_t buff{ident};
    for(int i = 0; i < (int) g[idx].size(); i++) {
      auto &e = g[idx][i];
      e.ndp = buff;
      e.dp = gg(par == e.to ? top : subdp[e.to], e.data);
      buff = f(buff, e.dp);
    }
    dp[idx] = buff;
    buff = ident;
    for(int i = (int) g[idx].size() - 1; i >= 0; i--) {
      auto &e = g[idx][i];
      if(e.to != par) dfs_all(e.to, idx, f(e.ndp, buff));
      e.ndp = f(e.ndp, buff);
      buff = f(buff, e.dp);
    }
  }

  vector< sum_t > build() {
    dfs_sub(0, -1);
    dfs_all(0, -1, ident);
    return dp;
  }
};

modint result=0;
template<typename T1,typename T2>
void dfs(ll k,ll par,ReRooting<T1,T2>&reroot,ll num){
  vector<modint>ret(num,1);
  for(auto e:reroot.g[k]){
    if(e.to==par){
      //cout<<k spa e.to<<" par ";debug(e.dp,num);
      ret[0]=0;
      rep(i,1,num)ret[i]*=e.dp[i-1];
    }
    else{
      //cout<<k spa e.to<<" ";debug(e.dp,num);
      rep(i,0,num)ret[i]*=e.dp[i];
      dfs(e.to,k,reroot,num);
    }
  }
  //cout<<k<<endl;
  //debug(ret,num);
  for(auto z:ret)result+=z;
}
int main(){
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);
  ll res=0,buf=0;
  bool judge = true;
  ll n,k;cin>>n>>k;
  auto f1=[&](vector<modint>a,vector<modint>b){
    vector<modint>ret(k);
    rep(i,0,k){
      ret[i]=a[i]*b[i];
    }
    return ret;
  };
  auto f2=[&](vector<modint>v,ll tmp){
    rep(i,0,k-1)v[i+1]+=v[i];
    //debug(v,k);
    return v;
  };
  vector<modint>iden(k,1);
  ReRooting<vector<modint>,ll>reroot(n,f1,f2,iden);
  rep(i,0,n-1){
    ll a,b;cin>>a>>b;a--;b--;
    reroot.add_edge(a,b,0);
  }
  auto v=reroot.build();
  //rep(i,0,n)debug(v[i],k);
  dfs(0,-1,reroot,k);
  cout<<result<<endl;
  return 0;
}
0