結果

問題 No.439 チワワのなる木
ユーザー miyo2580miyo2580
提出日時 2023-12-03 23:04:14
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
WA  
実行時間 -
コード長 6,939 bytes
コンパイル時間 2,438 ms
コンパイル使用メモリ 217,564 KB
実行使用メモリ 69,632 KB
最終ジャッジ日時 2024-09-26 22:22:36
合計ジャッジ時間 4,782 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge1
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 22 ms
18,816 KB
testcase_01 AC 21 ms
18,880 KB
testcase_02 AC 21 ms
18,944 KB
testcase_03 AC 22 ms
18,720 KB
testcase_04 AC 22 ms
18,816 KB
testcase_05 AC 23 ms
18,688 KB
testcase_06 AC 22 ms
18,752 KB
testcase_07 AC 21 ms
18,880 KB
testcase_08 WA -
testcase_09 WA -
testcase_10 WA -
testcase_11 WA -
testcase_12 WA -
testcase_13 WA -
testcase_14 WA -
testcase_15 WA -
testcase_16 WA -
testcase_17 WA -
testcase_18 WA -
testcase_19 WA -
testcase_20 WA -
testcase_21 WA -
testcase_22 WA -
testcase_23 WA -
testcase_24 AC 152 ms
63,616 KB
testcase_25 AC 81 ms
34,228 KB
testcase_26 WA -
testcase_27 AC 112 ms
69,632 KB
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ソースコード

diff # 

#include <bits/stdc++.h>
using namespace std;
#define repd(i,a,b) for (ll i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
#define all(x) (x).begin(),(x).end()
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
typedef long long ll;
typedef pair<ll,ll> P;
typedef vector<ll> vec;
using Graph = vector<vector<ll>>;
const long long INF = 1LL<<60;
const long long MOD = 1000000007;

//https://nyaannyaan.github.io/library/graph/graph-template.hpp
template <typename T>
struct edge {
  int src, to;
  T cost;

  edge(int _to, T _cost) : src(-1), to(_to), cost(_cost) {}
  edge(int _src, int _to, T _cost) : src(_src), to(_to), cost(_cost) {}

  edge &operator=(const int &x) {
    to = x;
    return *this;
  }

  operator int() const { return to; }
};
template <typename T>
using Edges = vector<edge<T>>;
template <typename T>
using WeightedGraph = vector<Edges<T>>;
using UnweightedGraph = vector<vector<int>>;

// Input of (Unweighted) Graph
UnweightedGraph graph(int N, int M = -1, bool is_directed = false,
                      bool is_1origin = true) {
  UnweightedGraph g(N);
  if (M == -1) M = N - 1;
  for (int _ = 0; _ < M; _++) {
    int x, y;
    cin >> x >> y;
    if (is_1origin) x--, y--;
    g[x].push_back(y);
    if (!is_directed) g[y].push_back(x);
  }
  return g;
}

// Input of Weighted Graph
template <typename T>
WeightedGraph<T> wgraph(int N, int M = -1, bool is_directed = false,
                        bool is_1origin = true) {
  WeightedGraph<T> g(N);
  if (M == -1) M = N - 1;
  for (int _ = 0; _ < M; _++) {
    int x, y;
    cin >> x >> y;
    T c;
    cin >> c;
    if (is_1origin) x--, y--;
    g[x].emplace_back(x, y, c);
    if (!is_directed) g[y].emplace_back(y, x, c);
  }
  return g;
}

// Input of Edges
template <typename T>
Edges<T> esgraph(int N, int M, int is_weighted = true, bool is_1origin = true) {
  Edges<T> es;
  for (int _ = 0; _ < M; _++) {
    int x, y;
    cin >> x >> y;
    T c;
    if (is_weighted)
      cin >> c;
    else
      c = 1;
    if (is_1origin) x--, y--;
    es.emplace_back(x, y, c);
  }
  return es;
}

// Input of Adjacency Matrix
template <typename T>
vector<vector<T>> adjgraph(int N, int M, T INF, int is_weighted = true,
                           bool is_directed = false, bool is_1origin = true) {
  vector<vector<T>> d(N, vector<T>(N, INF));
  for (int _ = 0; _ < M; _++) {
    int x, y;
    cin >> x >> y;
    T c;
    if (is_weighted)
      cin >> c;
    else
      c = 1;
    if (is_1origin) x--, y--;
    d[x][y] = c;
    if (!is_directed) d[y][x] = c;
  }
  return d;
}

/**
 * @brief グラフテンプレート
 * @docs docs/graph/graph-template.md
 */

//https://nyaannyaan.github.io/library/tree/rerooting.hpp

// Rerooting
// f1(c1, c2) ... merge value of child node
// f2(memo[i], chd, par) ... return value from child node to parent node
// memo[i] ... result of subtree rooted i
// dp[i] ... result of tree rooted i
template <typename T, typename G, typename F1, typename F2>
struct Rerooting {
  const G &g;
  const F1 f1;
  const F2 f2;
  vector<T> memo, dp;
  T I;

  Rerooting(const G &_g, const F1 _f1, const F2 _f2, const T &I_)
      : g(_g), f1(_f1), f2(_f2), memo(g.size(), I_), dp(g.size(), I_), I(I_) {
    dfs(0, -1);
    efs(0, -1, I);
  }

  const T &operator[](int i) const { return dp[i]; }

  void dfs(int cur, int par) {
    for (auto &dst : g[cur]) {
      if (dst == par) continue;
      dfs(dst, cur);
      memo[cur] = f1(memo[cur], f2(memo[dst], dst, cur));
    }
  }

  void efs(int cur, int par, const T &pval) {
    // get cumulative sum
    vector<T> buf;
    for (auto dst : g[cur]) {
      if (dst == par) continue;
      buf.push_back(f2(memo[dst], dst, cur));
    }
    vector<T> head(buf.size() + 1), tail(buf.size() + 1);
    head[0] = tail[buf.size()] = I;
    for (int i = 0; i < (int)buf.size(); i++) head[i + 1] = f1(head[i], buf[i]);
    for (int i = (int)buf.size() - 1; i >= 0; i--)
      tail[i] = f1(tail[i + 1], buf[i]);

    // update
    dp[cur] = par == -1 ? head.back() : f1(pval, head.back());

    // propagate
    int idx = 0;
    for (auto &dst : g[cur]) {
      if (dst == par) continue;
      efs(dst, cur, f2(f1(pval, f1(head[idx], tail[idx + 1])), cur, dst));
      idx++;
    }
  }
};

/**
 * @brief Rerooting(全方位木DP)
 * @docs docs/tree/rerooting.md
 */

// auto mod int
// https://youtu.be/L8grWxBlIZ4?t=9858
// https://youtu.be/ERZuLAxZffQ?t=4807 : optimize
// https://youtu.be/8uowVvQ_-Mo?t=1329 : division
const int mod = 1000000007;
struct mint {
  ll x; // typedef long long ll;
  mint(ll x=0):x((x%mod+mod)%mod){}
  mint operator-() const { return mint(-x);}
  mint& operator+=(const mint a) {
    if ((x += a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    if ((x += mod-a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}
  mint operator+(const mint a) const { return mint(*this) += a;}
  mint operator-(const mint a) const { return mint(*this) -= a;}
  mint operator*(const mint a) const { return mint(*this) *= a;}
  mint pow(ll t) const {
    if (!t) return 1;
    mint a = pow(t>>1);
    a *= a;
    if (t&1) a *= *this;
    return a;
  }

  // for prime mod
  mint inv() const { return pow(mod-2);}
  mint& operator/=(const mint a) { return *this *= a.inv();}
  mint operator/(const mint a) const { return mint(*this) /= a;}
};
istream& operator>>(istream& is, mint& a) { return is >> a.x;}
ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}

// combination mod prime
// https://www.youtube.com/watch?v=8uowVvQ_-Mo&feature=youtu.be&t=1619
struct combination {
  vector<mint> fact, ifact;
  combination(int n):fact(n+1),ifact(n+1) {
    assert(n < mod);
    fact[0] = 1;
    for (int i = 1; i <= n; ++i) fact[i] = fact[i-1]*i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i) ifact[i-1] = ifact[i]*i;
  }
  mint operator()(int n, int k) {
    if (k < 0 || k > n) return 0;
    return fact[n]*ifact[k]*ifact[n-k];
  }
  mint p(int n,int k){
      return fact[n]*ifact[n-k];
  }
} C(1000005);

using F=tuple<ll,ll,ll>;

int main()
{  
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll n;cin>>n;
    string s;cin>>s;
    auto g=graph(n,n-1,0,1);
    auto f1=[&](F x,F y){
      auto[a,b,c]=x;
      auto[d,e,f]=y;
      c=a*e+b*d;
      a+=d;
      b+=e;
      return F(a,b,c);
    };
    auto f2=[&](F x,int ch,int p){
      auto[a,b,c]=x;
      if(s[ch]=='w')a++;
      else b++;
      return F(a,b,c);
    };
    Rerooting<F,decltype(g),decltype(f1),decltype(f2)> dp(g,f1,f2,{0,0,0});
    ll cnt=0;
    rep(i,n)if(s[i]=='w')cnt++;
    ll ans=0;
    ll id=0;
    for(auto x:dp.dp){
      auto[A,B,C]=x;
      if(s[id]=='w')ans+=get<2>(x);
      id++;
    }
    cout<<ans<<endl;
    return 0;
}
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