Submission #1263364

#	Time	Username	Problem	Language	Result	Execution time	Memory
1263364		amigoo99234	Harbingers (CEOI09_harbingers)	C++20	20 / 100	164 ms	131072 KiB

harbingers

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

#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
using ll = long long;

const ll N = (ll)1e9 + 5;
const ll DEFAULT = LLONG_MAX;  // for min Li Chao

struct Line {
    ll m, c;
    Line(ll _m = 0, ll _c = DEFAULT) : m(_m), c(_c) {}
    ll eval(ll x) const {
        __int128 val = (__int128)m * (__int128)x + (__int128)c;
        if (val > ( (__int128)LLONG_MAX / 2 )) return LLONG_MAX;
        if (val < ( (__int128)LLONG_MIN / 2 )) return LLONG_MIN;
        return (ll)val;
    }
    ll operator()(ll x) const { return eval(x); }
};

struct Node {
    Line line;
    Node* left = nullptr;
    Node* right = nullptr;
    Node(const Line &L = Line()) : line(L) {}
};

// change record: pointer change or line change
struct Change {
    bool isLineChange;
    // pointer change
    Node** ptrAddr = nullptr;
    Node* oldPtr = nullptr;
    // line change
    Node* node = nullptr;
    Line oldLine;
    Change(Node** p, Node* old) : isLineChange(false), ptrAddr(p), oldPtr(old) {}
    Change(Node* nd, const Line &oldL) : isLineChange(true), node(nd), oldLine(oldL) {}
};

vector<Change> changeLog;
vector<int> insertCheckpoints;

// recursively delete a subtree (post-order)
void deleteSubtree(Node* cur) {
    if (!cur) return;
    if (cur->left) { deleteSubtree(cur->left); cur->left = nullptr; }
    if (cur->right) { deleteSubtree(cur->right); cur->right = nullptr; }
    delete cur;
}

inline void record_ptr(Node*& p) {
    changeLog.emplace_back(&p, p);
}

inline void record_line(Node* node) {
    changeLog.emplace_back(node, node->line);
}

void rollbackTo(int checkpoint) {
    while ((int)changeLog.size() > checkpoint) {
        Change ch = changeLog.back();
        changeLog.pop_back();
        if (!ch.isLineChange) {
            // pointer-change rollback:
            Node** addr = ch.ptrAddr;
            Node* cur = *addr;
            // If the current pointer differs from oldPtr, delete the current subtree first
            if (cur != ch.oldPtr && cur != nullptr) {
                deleteSubtree(cur);
            }
            // restore old pointer value
            *addr = ch.oldPtr;
        } else {
            // line-change rollback
            ch.node->line = ch.oldLine;
        }
    }
}

void rollbackLastInsert() {
    if (!insertCheckpoints.empty()) {
        rollbackTo(insertCheckpoints.back());
        insertCheckpoints.pop_back();
    }
}

// insert impl (min Li Chao)
void insert_impl(Line newLine, Node*& root, ll l, ll r) {
    if (!root) {
        record_ptr(root);               // record pointer before changing it
        root = new Node(newLine);
        return;
    }

    ll m = (l + r) / 2;
    bool lef = newLine.eval(l) < root->line.eval(l);
    bool mid = newLine.eval(m) < root->line.eval(m);

    if (mid) {
        record_line(root);             // record the node->line before swapping
        swap(root->line, newLine);
    }

    if (r - l == 1) return;

    if (lef != mid) {
        insert_impl(newLine, root->left, l, m);
    } else {
        insert_impl(newLine, root->right, m, r);
    }
}

void insert(Line newLine, Node*& root, ll l = -N, ll r = +N) {
    insertCheckpoints.push_back((int)changeLog.size());
    insert_impl(newLine, root, l, r);
}

ll query(ll x, Node* root, ll l = -N, ll r = +N) {
    if (!root) return DEFAULT;
    ll m = (l + r) / 2;
    ll res = root->line.eval(x);
    if (r - l == 1) return res;
    if (x < m) return min(res, query(x, root->left, l, m));
    else return min(res, query(x, root->right, m, r));
}

/* ----------------- rest of your program ----------------- */

Node *root = nullptr;
int n;
vector<int> v, c;
vector<vector<pair<int,int>>> adj;
vector<ll> dp;

void dfs(int node , int p = -1 , int d = 0)
{
    if(p == -1) dp[node] = 0;
    else {
        ll q = query(v[node], root);
        dp[node] = q + (ll)v[node] * (ll)d + (ll)c[node];
    }

    insert(Line(-d , dp[node]) , root);

    for(auto [child , len] : adj[node]) {
        if(child == p) continue;
        dfs(child , node , d + len);
    }
    rollbackLastInsert();
}

int main() {
    fast;

    cin >> n;
    dp.assign(n, 0);
    v.assign(n, 0);
    c.assign(n, 0);
    adj.assign(n, {});

    for (int i = 0; i < n - 1; ++i) {
        int u, vv, d;
        cin >> u >> vv >> d;
        --u; --vv;
        adj[u].emplace_back(vv, d);
        adj[vv].emplace_back(u, d);
    }
    for (int i = 1; i < n; ++i) cin >> c[i] >> v[i];

    dfs(0);

    for(int i = 1 ; i < n ; i++) cout << dp[i] << " ";
    cout << '\n';
    return 0;
}

• Subtask 1: 20 / 100