結果

問題 No.2598 Kadomatsu on Tree
ユーザー AngrySadEight
提出日時 2023-12-19 17:29:17
言語 C++17(gcc12)
(gcc 12.3.0 + boost 1.87.0)
結果
AC  
実行時間 556 ms / 2,000 ms
コード長 5,181 bytes
コンパイル時間 17,624 ms
コンパイル使用メモリ 263,520 KB
最終ジャッジ日時 2025-02-18 12:17:59
ジャッジサーバーID
（参考情報） 		judge4 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 60
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 target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <algorithm>
#include <atcoder/all>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define all(v) v.begin(), v.end()
#define mod1 1000000007
#define mod2 998244353
#define mod3 100000007
#define vi vector<int>
#define vs vector<string>
#define vc vector<char>
#define vl vector<ll>
#define vb vector<bool>
#define vvi vector<vector<int>>
#define vvc vector<vector<char>>
#define vvl vector<vector<ll>>
#define vvb vector<vector<bool>>
#define vvvi vector<vector<vector<int>>>
#define vvvl vector<vector<vector<ll>>>
#define pii pair<int, int>
#define pil pair<int, ll>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define vpii vector<pair<int, int>>
#define vpll vector<pair<ll, ll>>
#define vvpii vector<vector<pair<int, int>>>
#define vvpll vector<vector<pair<ll, ll>>>

using mint = modint998244353;

template <typename T>
void debug(T e) {
    cerr << e << endl;
}

template <typename T>
void debug(vector<T> &v) {
    rep(i, v.size()) { cerr << v[i] << " "; }
    cerr << endl;
}

template <typename T>
void debug(vector<vector<T>> &v) {
    rep(i, v.size()) {
        rep(j, v[i].size()) { cerr << v[i][j] << " "; }
        cerr << endl;
    }
}

template <typename T>
void debug(vector<pair<T, T>> &v) {
    rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; }
}

template <typename T>
void debug(set<T> &st) {
    for (auto itr = st.begin(); itr != st.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(multiset<T> &ms) {
    for (auto itr = ms.begin(); itr != ms.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(map<T, T> &mp) {
    for (auto itr = mp.begin(); itr != mp.end(); itr++) {
        cerr << itr->first << " " << itr->second << endl;
    }
}

void debug_out() { cerr << endl; }

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

void dfs(vector<vector<ll>> &graph, vector<bool> &isvisited, vector<ll> &prev,
         vector<ll> &dp, ll v) {
    isvisited[v] = true;
    ll dp_val = 1;
    for (ll i = 0; i < graph[v].size(); i++) {
        if (isvisited[graph[v][i]]) {
            continue;
        }
        prev[graph[v][i]] = v;
        dfs(graph, isvisited, prev, dp, graph[v][i]);
        dp_val += dp[graph[v][i]];
    }
    dp[v] = dp_val;
}

int main() {
    ll N;
    cin >> N;
    assert(N >= 3);
    assert(N <= 200000);
    vector<ll> U(N - 1);
    vector<ll> V(N - 1);
    for (ll i = 0; i < N - 1; i++) {
        cin >> U[i] >> V[i];
        assert(U[i] >= 1);
        assert(V[i] <= N);
        assert(U[i] != V[i]);
        U[i]--;
        V[i]--;
    }
    vector<vector<ll>> graph(N, vector<ll>(0));
    for (ll i = 0; i < N - 1; i++) {
        graph[U[i]].push_back(V[i]);
        graph[V[i]].push_back(U[i]);
    }
    vector<ll> A(N);
    for (ll i = 0; i < N; i++) {
        cin >> A[i];
        assert(A[i] >= 1);
        assert(A[i] <= 1000000000);
    }
    // 根つき木を適当にとり，部分木のサイズを求める
    vector<ll> dp(N, 0);
    vector<bool> isvisited(N, false);
    vector<ll> prev(N, -1);
    dfs(graph, isvisited, prev, dp, 0);
    assert(prev[0] == -1);
    for (ll i = 1; i < N; i++) {
        assert(prev[i] != -1);
    }

    ll ans = 0;
    for (ll i = 0; i < N; i++) {
        ll plus = 0;
        ll minus = 0;

        ll rem = N - 1;
        for (ll j = 0; j < graph[i].size(); j++) {
            if (prev[i] != graph[i][j]) {
                rem -= dp[graph[i][j]];
            }
        }
        for (ll j = 0; j < graph[i].size(); j++) {
            ll subsize = dp[graph[i][j]];
            if (prev[i] == graph[i][j]) {
                subsize = rem;
            }
            if (A[i] < A[graph[i][j]]) {
                plus += subsize;
            }
            if (A[i] > A[graph[i][j]]) {
                minus += subsize;
            }
        }
        for (ll j = 0; j < graph[i].size(); j++) {
            ll subsize = dp[graph[i][j]];
            if (prev[i] == graph[i][j]) {
                subsize = rem;
            }
            if (A[i] < A[graph[i][j]]) {
                ans += subsize * (plus - subsize);
                ans %= mod2;
                plus -= subsize;
            }
            if (A[i] > A[graph[i][j]]) {
                ans += subsize * (minus - subsize);
                ans %= mod2;
                minus -= subsize;
            }
        }
        // debug_out(i, plus, minus, ans);
    }
    cout << ans << endl;
}
0