結果

問題 No.1833 Subway Planning
ユーザー yuto1115yuto1115
提出日時 2022-02-04 23:00:41
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 438 ms / 4,000 ms
コード長 10,644 bytes
コンパイル時間 3,130 ms
コンパイル使用メモリ 225,560 KB
実行使用メモリ 84,224 KB
最終ジャッジ日時 2024-06-11 12:37:17
合計ジャッジ時間 8,476 ms
ジャッジサーバーID
（参考情報） 		judge1 / 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
5,248 KB
testcase_02 AC 2 ms
5,376 KB
testcase_03 AC 2 ms
5,376 KB
testcase_04 AC 230 ms
84,224 KB
testcase_05 AC 269 ms
84,224 KB
testcase_06 AC 161 ms
84,224 KB
testcase_07 AC 242 ms
84,096 KB
testcase_08 AC 239 ms
82,304 KB
testcase_09 AC 438 ms
84,224 KB
testcase_10 AC 184 ms
81,256 KB
testcase_11 AC 165 ms
81,284 KB
testcase_12 AC 164 ms
81,388 KB
testcase_13 AC 177 ms
81,384 KB
testcase_14 AC 151 ms
79,872 KB
testcase_15 AC 187 ms
79,872 KB
testcase_16 AC 198 ms
80,000 KB
testcase_17 AC 204 ms
80,000 KB
testcase_18 AC 195 ms
75,392 KB
testcase_19 AC 180 ms
80,128 KB
testcase_20 AC 137 ms
62,848 KB
testcase_21 AC 372 ms
83,164 KB
testcase_22 AC 315 ms
80,600 KB
testcase_23 AC 2 ms
5,376 KB
testcase_24 AC 2 ms
5,376 KB
testcase_25 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 # 

#include<bits/stdc++.h>
#define overload4(_1, _2, _3, _4, name, ...) name
#define rep1(i, n) for (ll i = 0; i < ll(n); ++i)
#define rep2(i, s, n) for (ll i = ll(s); i < ll(n); ++i)
#define rep3(i, s, n, d) for(ll i = ll(s); i < ll(n); i+=d)
#define rep(...) overload4(__VA_ARGS__,rep3,rep2,rep1)(__VA_ARGS__)
#define rrep1(i, n) for (ll i = ll(n)-1; i >= 0; i--)
#define rrep2(i, n, t) for (ll i = ll(n)-1; i >= (ll)t; i--)
#define rrep3(i, n, t, d) for (ll i = ll(n)-1; i >= (ll)t; i-=d)
#define rrep(...) overload4(__VA_ARGS__,rrep3,rrep2,rrep1)(__VA_ARGS__)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define SUM(a) accumulate(all(a),0LL)
#define MIN(a) *min_element(all(a))
#define MAX(a) *max_element(all(a))
#define SORT(a) sort(all(a));
#define REV(a) reverse(all(a));
#define SZ(a) int(a.size())
#define popcount(x) __builtin_popcountll(x)
#define pf push_front
#define pb push_back
#define ef emplace_front
#define eb emplace_back
#define ppf pop_front
#define ppb pop_back
#ifdef __LOCAL
#define debug(...) { cout << #__VA_ARGS__; cout << ": "; print(__VA_ARGS__); cout << flush; }
#else
#define debug(...) void(0);
#endif
#define INT(...) int __VA_ARGS__;scan(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;scan(__VA_ARGS__)
#define STR(...) string __VA_ARGS__;scan(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;scan(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__;scan(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__;scan(__VA_ARGS__)
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using LP = pair<ll, ll>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vd = vector<double>;
using vvd = vector<vd>;
using vs = vector<string>;
using vc = vector<char>;
using vvc = vector<vc>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vp = vector<P>;
using vvp = vector<vp>;
template<class T>
using PQ = priority_queue<pair<T, int>, vector<pair<T, int>>, greater<pair<T, int>>>;

template<class S, class T>
istream &operator>>(istream &is, pair<S, T> &p) { return is >> p.first >> p.second; }

template<class S, class T>
ostream &operator<<(ostream &os, const pair<S, T> &p) { return os << '{' << p.first << ", " << p.second << '}'; }

template<class S, class T, class U>
istream &operator>>(istream &is, tuple<S, T, U> &t) { return is >> get<0>(t) >> get<1>(t) >> get<2>(t); }

template<class S, class T, class U>
ostream &operator<<(ostream &os, const tuple<S, T, U> &t) {
    return os << '{' << get<0>(t) << ", " << get<1>(t) << ", " << get<2>(t) << '}';
}

template<class T>
istream &operator>>(istream &is, vector<T> &v) {
    for (T &t: v) { is >> t; }
    return is;
}

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    os << '[';
    rep(i, v.size()) os << v[i] << (i == int(v.size() - 1) ? "" : ", ");
    return os << ']';
}

template<class T>
ostream &operator<<(ostream &os, const deque<T> &v) {
    os << '[';
    rep(i, v.size()) os << v[i] << (i == int(v.size() - 1) ? "" : ", ");
    return os << ']';
}

template<class T>
ostream &operator<<(ostream &os, const set<T> &st) {
    os << '{';
    auto it = st.begin();
    while (it != st.end()) {
        os << (it == st.begin() ? "" : ", ") << *it;
        it++;
    }
    return os << '}';
}

template<class T>
ostream &operator<<(ostream &os, const multiset<T> &st) {
    os << '{';
    auto it = st.begin();
    while (it != st.end()) {
        os << (it == st.begin() ? "" : ", ") << *it;
        it++;
    }
    return os << '}';
}

template<class T>
void vecout(const vector<T> &v, char div = '\n') {
    rep(i, v.size()) cout << v[i] << (i == int(v.size() - 1) ? '\n' : div);
}

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

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

void scan() {}

template<class Head, class... Tail>
void scan(Head &head, Tail &... tail) {
    cin >> head;
    scan(tail...);
}

template<class T>
void print(const T &t) { cout << t << '\n'; }

template<class Head, class... Tail>
void print(const Head &head, const Tail &... tail) {
    cout << head << ' ';
    print(tail...);
}

template<class... T>
void fin(const T &... a) {
    print(a...);
    exit(0);
}

template<class T>
vector<T> &operator+=(vector<T> &v, T x) {
    for (T &t: v) t += x;
    return v;
}

template<class T>
vector<T> &operator-=(vector<T> &v, T x) {
    for (T &t: v) t -= x;
    return v;
}

template<class T>
vector<T> &operator*=(vector<T> &v, T x) {
    for (T &t: v) t *= x;
    return v;
}

template<class T>
vector<T> &operator/=(vector<T> &v, T x) {
    for (T &t: v) t /= x;
    return v;
}

struct Init_io {
    Init_io() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
        cout.tie(nullptr);
        cout << boolalpha << fixed << setprecision(15);
        cerr << boolalpha << fixed << setprecision(15);
    }
} init_io;

const string yes[] = {"no", "yes"};
const string Yes[] = {"No", "Yes"};
const string YES[] = {"NO", "YES"};
const int inf = 1001001001;
const ll linf = 1001001001001001001;

void rearrange(const vi &) {}

template<class T, class... Tail>
void rearrange(const vi &ord, vector<T> &head, Tail &...tail) {
    assert(ord.size() == head.size());
    vector<T> ori = head;
    rep(i, ord.size()) head[i] = ori[ord[i]];
    rearrange(ord, tail...);
}

template<class T, class... Tail>
void sort_by(vector<T> &head, Tail &... tail) {
    vi ord(head.size());
    iota(all(ord), 0);
    sort(all(ord), [&](int i, int j) { return head[i] < head[j]; });
    rearrange(ord, head, tail...);
}

template<class T, class S>
vector<T> cumsum(const vector<S> &v, bool shift_one = true) {
    int n = v.size();
    vector<T> res;
    if (shift_one) {
        res.resize(n + 1);
        rep(i, n) res[i + 1] = res[i] + v[i];
    } else {
        res.resize(n);
        if (n) {
            res[0] = v[0];
            rep(i, 1, n) res[i] = res[i - 1] + v[i];
        }
    }
    return res;
}

vvi graph(int n, int m, bool directed = false, int origin = 1) {
    vvi G(n);
    rep(_, m) {
        INT(u, v);
        u -= origin, v -= origin;
        G[u].pb(v);
        if (!directed) G[v].pb(u);
    }
    return G;
}

template<class T>
vector<vector<pair<int, T>>> weighted_graph(int n, int m, bool directed = false, int origin = 1) {
    vector<vector<pair<int, T>>> G(n);
    rep(_, m) {
        int u, v;
        T w;
        scan(u, v, w);
        u -= origin, v -= origin;
        G[u].eb(v, w);
        if (!directed) G[v].eb(u, w);
    }
    return G;
}

template<class M>
class LCA {
    using S = typename M::S;
    int n;
    vector<vector<pair<int, S>>> G;
    vi dep;
    vvi par;
    vector<vector<S>> dp;
    
    void dfs(int u, int p, S ps, int d) {
        par[0][u] = p;
        dep[u] = d;
        dp[0][u] = ps;
        for (auto[v, s]: G[u]) if (v != p) dfs(v, u, s, d + 1);
    }
    
    void init() {
        n = G.size();
        dep.assign(n, -1);
        par.resize(30);
        dp.resize(30);
        rep(i, 30) {
            par[i].resize(n);
            dp[i].assign(n, M::e);
        }
        rep(i, n) if (dep[i] == -1) dfs(i, -1, M::e, 0);
        rep(k, 29) rep(i, n) {
                if (par[k][i] < 0) par[k + 1][i] = -1;
                else {
                    par[k + 1][i] = par[k][par[k][i]];
                    dp[k + 1][i] = M::op(dp[k][i], dp[k][par[k][i]]);
                }
            }
    }

public:
    LCA(const vector<vector<pair<int, S>>> &G) : G(G) { init(); }
    
    int operator()(int u, int v) {
        if (dep[u] > dep[v]) swap(u, v);
        rep(k, 30) if ((dep[v] - dep[u]) >> k & 1) v = par[k][v];
        if (u == v) return u;
        rrep(k, 30) {
            if (par[k][u] != par[k][v]) {
                u = par[k][u];
                v = par[k][v];
            }
        }
        assert(par[0][u] == par[0][v]);
        return par[0][u];
    }
    
    int dist(int u, int v) {
        int w = this->operator()(u, v);
        return dep[u] + dep[v] - dep[w] * 2;
    }
    
    S prod(int u, int v) {
        int l = this->operator()(u, v);
        int du = dist(u, l), dv = dist(v, l);
        S res = M::e;
        rep(k, 30) {
            if (du >> k & 1) {
                res = M::op(res, dp[k][u]);
                u = par[k][u];
            }
            if (dv >> k & 1) {
                res = M::op(res, dp[k][v]);
                v = par[k][v];
            }
        }
        return res;
    }
    
    // path from u to v (including u, v)
    vi path(int u, int v) {
        int l = this->operator()(u, v);
        vi ul, vl;
        while (l != u) {
            ul.pb(u);
            u = par[0][u];
        }
        while (l != v) {
            vl.pb(v);
            v = par[0][v];
        }
        ul.pb(l);
        ul.insert(ul.end(), rall(vl));
        return ul;
    }
};

class M {
public:
    using S = int;
    
    static constexpr S e = inf;
    
    // requirement : op(l, r) = op(r, l)
    static constexpr S op(const S &l, const S &r) {
        return min(l, r);
    }
};

int main() {
    INT(n);
    vi a(n - 1), b(n - 1), c(n - 1);
    vvp G(n);
    rep(i, n - 1) {
        scan(a[i], b[i], c[i]);
        --a[i], --b[i];
        G[a[i]].eb(b[i], c[i]);
        G[b[i]].eb(a[i], c[i]);
    }
    LCA<M> lca(G);
    sort_by(c, a, b);
    int u = -1, v = -1, uv = -1;
    int mx = MAX(c);
    rrep(t, n - 1) {
        int i = a[t], j = b[t];
        rep(_, 1) {
            if (u == -1) {
                u = i, v = j;
                uv = lca.dist(u, v);
                continue;
            }
            int ui = lca.dist(u, i);
            int uj = lca.dist(u, j);
            int vi = lca.dist(v, i);
            int vj = lca.dist(v, j);
            if (uv == ui + 1 + vj) continue;
            if (uv == uj + 1 + vi) continue;
            if (ui == uv + vj + 1) {
                v = i;
                uv = ui;
                continue;
            }
            if (uj == uv + vi + 1) {
                v = j;
                uv = uj;
                continue;
            }
            if (vi == uv + uj + 1) {
                u = i;
                uv = vi;
                continue;
            }
            if (vj == uv + ui + 1) {
                u = j;
                uv = vj;
                continue;
            }
            fin(c[t]);
        }
        int mn = lca.prod(u, v);
        if (!t or mx - mn > c[t - 1]) fin(min(c[t], mx - mn));
    }
}
0