Submission #1230789

#TimeUsernameProblemLanguageResultExecution timeMemory
1230789ballsFactories (JOI14_factories)C++20
0 / 100
22 ms24132 KiB
#include "factories.h"
#include<bits/stdc++.h>
using namespace std;

const int MAXN = 5e5 + 7;
const int LOG = 20;

vector<pair<int, int>> tree[MAXN];
int up[MAXN][LOG], depth[MAXN], tin[MAXN], tout[MAXN];
long long dist[MAXN];
int tim;

void dfs(int u, int p) {
    tin[u] = ++tim;
    up[u][0] = p;
    for (int i = 1; i < LOG; i++) {
        up[u][i] = up[up[u][i - 1]][i - 1];
    }
    for (auto [v, w] : tree[u]) {
        if (v == p) {
            continue;
        }
        depth[v] = depth[u] + 1;
        dist[v] = dist[u] + w;
        dfs(v, u);
    }

    tout[u] = ++tim;
}

bool ck(int u, int v) {
    return tin[u] <= tin[v] && tout[u] >= tout[v];
}

int lca(int u, int v) {
    if (ck(u, v)) {
        return u;
    }
    if (ck(v, u)) {
        return v;
    }
    for (int i = LOG - 1; i >= 0; i--) {
        if (!ck(up[u][i], v)) {
            u = up[u][i];
        }
    }
    return up[u][0];
}

long long get_dist(int u, int v) {
    int anc = lca(u, v);
    return dist[u] + dist[v] - 2 * dist[anc];
}

void Init(int N, int A[], int B[], int D[]) {
    for (int i = 0; i < N - 1; i++) {
        tree[A[i]].emplace_back(B[i], D[i]);
        tree[B[i]].emplace_back(A[i], D[i]);
    }
    dfs(0, 0);
}

vector<int> vtree[MAXN];
bool isX[MAXN], isY[MAXN];

long long res;

void dfs_virtual(int u) {
    long long bestX = isX[u] ? 0 : 1e18;
    long long bestY = isY[u] ? 0 : 1e18;

    for (int v : vtree[u]) {
        dfs_virtual(v);
        long long d = get_dist(u, v);
        bestX = min(bestX, (long long) (isX[v] ? d : 1e18));
        bestY = min(bestY, (long long) (isY[v] ? d : 1e18));
        res = min(res, (long long) bestX + bestY);
    }

    isX[u] = (bestX == 0);
    isY[u] = (bestY == 0);
}

long long Query(int S, int X[], int T, int Y[]) {
    vector<int> nodes;
    for (int i = 0; i < S; i++) {
        nodes.push_back(X[i]);
        isX[X[i]] = true;
    }
    for (int i = 0; i < T; i++) {
        nodes.push_back(Y[i]);
        isY[Y[i]] = true;
    }
    sort(nodes.begin(), nodes.end(), [](int a, int b) {
        return tin[a] < tin[b];
    });
    int sz = nodes.size();
    for (int i = 0; i+1 < sz; ++i) {
        nodes.push_back(lca(nodes[i], nodes[i+1]));
    }
    sort(nodes.begin(), nodes.end(), [](int a, int b) {
        return tin[a] < tin[b];
    });
    nodes.erase(unique(nodes.begin(), nodes.end()), nodes.end());
    vector<int> stk;
    for (int u : nodes) {
        vtree[u].clear();
    }
    for (int u : nodes) {
        while (!stk.empty() && !ck(stk.back(), u)) stk.pop_back();
        if (!stk.empty()) {
            vtree[stk.back()].push_back(u);
        }
        stk.push_back(u);
    }
    res = 1e18;
    dfs_virtual(nodes[0]);
    for (int u : nodes) {
        isX[u] = isY[u] = false;
    }
    return res;
}
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