제출 #894013

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
894013		azosi	Min-max tree (BOI18_minmaxtree)	C++17	100 / 100	278 ms	30032 KiB

minmaxtree

#include <bits/stdc++.h>

using namespace std;
const int MAX_N = 70070;
const int INF = 1e9 + 100;
int n, q;

struct SegmentTree {
    typedef int (*F)(int, int);

    F merge;
    int identity;
    int tree[MAX_N * 4]{}, lazy[MAX_N * 4]{};

    SegmentTree(F func, int identity) : merge(func), identity(identity) {
        for (int i = 0; i < MAX_N * 4; ++i) tree[i] = lazy[i] = identity;
    }

    void push(int node, int l, int r) {
        if (lazy[node] != identity) {
            tree[node] = merge(tree[node], lazy[node]);
            if (l != r) {
                lazy[node * 2] = merge(lazy[node * 2], lazy[node]);
                lazy[node * 2 + 1] = merge(lazy[node * 2 + 1], lazy[node]);
            }
        }
        lazy[node] = identity;
    }

    void update(int s, int e, int val, int node = 1, int l = 1, int r = MAX_N) {
        push(node, l, r);
        if (e < l || r < s) return;
        if (s <= l && r <= e) {
            lazy[node] = val;
            push(node, l, r);
            return;
        }
        int mid = (l + r) / 2;
        update(s, e, val, node * 2, l, mid);
        update(s, e, val, node * 2 + 1, mid + 1, r);
        tree[node] = merge(tree[node * 2], tree[node * 2 + 1]);
    }

    int query(int s, int e, int node = 1, int l = 1, int r = MAX_N) {
        push(node, l, r);
        if (e < l || r < s) return identity;
        if (s <= l && r <= e) return tree[node];
        int mid = (l + r) / 2;
        return merge(query(s, e, node * 2, l, mid), query(s, e, node * 2 + 1, mid + 1, r));
    }

};

int _mn(int a, int b) {
    return min(a, b);
}

int _mx(int a, int b) {
    return max(a, b);
}

SegmentTree minSeg(_mn, INF), maxSeg(_mx, -INF);
int in[MAX_N], dep[MAX_N], par[MAX_N], top[MAX_N], sz[MAX_N], chk[MAX_N];
int maxi[MAX_N], mini[MAX_N], cnt[MAX_N], ans[MAX_N], vis[MAX_N];
int pv;
map<int, int> toIdx;
vector<int> bench[MAX_N];
vector<int> g[MAX_N], inp[MAX_N];

void dfs(int v = 1) {
    chk[v] = 1;
    for (auto i: inp[v]) {
        if (chk[i]) continue;
        chk[i] = 1;
        g[v].push_back(i);
        dfs(i);
    }
}

void dfs1(int v = 1) {
    sz[v] = 1;
    for (auto &i: g[v]) {
        dep[i] = dep[v] + 1;
        par[i] = v;
        dfs1(i);
        sz[v] += sz[i];
        if (sz[i] > sz[g[v][0]]) swap(i, g[v][0]);
    }
}

void dfs2(int v = 1) {
    in[v] = ++pv;
    for (auto i: g[v]) {
        top[i] = i == g[v][0] ? top[v] : i;
        dfs2(i);
    }
}

void update(int a, int b, int k, bool op) {
    while (top[a] != top[b]) {
        if (dep[top[a]] < dep[top[b]]) swap(a, b);
        int st = top[a];
        op ? minSeg.update(in[st], in[a], k) : maxSeg.update(in[st], in[a], k);
        a = par[st];
    }
    if (dep[a] > dep[b]) swap(a, b);
    if (op == 1) minSeg.update(in[a] + 1, in[b], k);
    else maxSeg.update(in[a] + 1, in[b], k);
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n;
    top[1] = 1;
    for (int i = 2; i <= n; i++) {
        int s, e;
        cin >> s >> e;
        inp[s].push_back(e);
        inp[e].push_back(s);
    }
    dfs();
    dfs1();
    dfs2();

    cin >> q;
    vector<int> zz;
    for (int i = 0; i < q; i++) {
        char op;
        int x, y, z;
        cin >> op >> x >> y >> z;
        if (op == 'm') update(x, y, z, false);
        else update(x, y, z, true);
        zz.push_back(z);
    }

    for (int i = 0; i < q; i++) {
        toIdx[zz[i]] = i;
    }
    for (int i = 2; i <= n; i++) {
        maxi[i] = maxSeg.query(in[i], in[i]);
        mini[i] = minSeg.query(in[i], in[i]);
        if (maxi[i] != -INF) {
            bench[toIdx[maxi[i]]].push_back(i);
        }
        if (mini[i] != INF) {
            bench[toIdx[mini[i]]].push_back(i);
        }
    }

    for (auto &i: ans) i = INF;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    for (int i = 0; i < q; i++) {
        cnt[toIdx[zz[i]]] = bench[toIdx[zz[i]]].size();
        pq.push({cnt[toIdx[zz[i]]], i});
    }
    while (!pq.empty()) {
        auto [am, id] = pq.top();
        pq.pop();
        if (am != cnt[id]) continue;
        vis[id] = true;

        for (auto node: bench[id]) {
            if (ans[node] != INF) continue;
            ans[node] = zz[id];
            if (maxi[node] != -INF && !vis[toIdx[maxi[node]]]) {
                cnt[toIdx[maxi[node]]]--;
                pq.emplace(cnt[toIdx[maxi[node]]], toIdx[maxi[node]]);
            }
            if (mini[node] != INF && !vis[toIdx[mini[node]]]) {
                cnt[toIdx[mini[node]]]--;
                pq.emplace(cnt[toIdx[mini[node]]], toIdx[mini[node]]);
            }
            break;
        }

    }
    for (int i = 2; i <= n; i++) {
        cout << par[i] << " " << i << " ";
        if (ans[i] != INF) {
            cout << ans[i] << "\n";
        } else {
            cout << maxi[i] << '\n';
        }
    }
}

• Subtask 1: 7 / 7
• Subtask 2: 22 / 22
• Subtask 3: 29 / 29
• Subtask 4: 42 / 42