Submission #1095233

#TimeUsernameProblemLanguageResultExecution timeMemory
1095233IcelastFactories (JOI14_factories)C++17
100 / 100
3173 ms287148 KiB
#include "factories.h"
#include <iostream>
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const ll maxn = 2*1e5+5, INF = 4e18+9;
struct CentroidTree{
    int n;
    vector<int> pa;
    void cons(int n, vector<vector<int>> &adj){
        pa.resize(n+1, -1);
        vector<bool> ban(n+1, false);
        vector<int> sub(n+1);
        int tree_size;
        auto rt = [&](auto rt, int u, int p) -> void{
            sub[u] = 1;
            for(int v : adj[u]){
                if(v == p || ban[v]) continue;
                rt(rt, v, u);
                sub[u]+=sub[v];
            }
        };
        auto find = [&](auto find, int u, int p) -> int{
            for(int v : adj[u]){
                if(v == p || ban[v]) continue;
                if(sub[v]*2 > tree_size){
                    return find(find, v, u);
                }
            }
            return u;
        };
        auto build = [&](auto build, int u, int p) -> void{
            rt(rt, u, u);
            tree_size = sub[u];
            int c = find(find, u, u);
            ban[c] = true;
            pa[c] = p;
            for(int v : adj[c]){
                if(ban[v]) continue;
                build(build, v, c);
            }
        };
        build(build,  1, 0);
    };
};
struct Tree{
    int n, root;
    vector<int> depth, head, sz, pa;
    vector<int> f;
    void cons(int n, int root, vector<vector<int>> &adj){
        depth.resize(n+1, -1);
        head.resize(n+1);
        sz.resize(n+1, 0);
        pa.resize(n+1, -1);
        auto rootTree = [&](auto rootTree, int u, int p) -> void{
            depth[u] = depth[p]+1;
            pa[u] = p;
            sz[u] = 1;
            for(int v : adj[u]){
                if(v == p) continue;
                rootTree(rootTree, v, u);
                sz[u] += sz[v];
            }
        };
        rootTree(rootTree, root, 0);
        auto decompose = [&](auto decompose, int u, int h) -> void{
            head[u] = h;
            int heavy = -1;
            for(int v : adj[u]){
                if(v == pa[u]) continue;
                if(heavy == -1 || sz[heavy] < sz[v]) heavy = v;
            }
            if(heavy != -1) decompose(decompose, heavy, h);
            for(int v : adj[u]){
                if(v == pa[u] || v == heavy) continue;
                decompose(decompose, v, v);
            }
        };
        decompose(decompose, root, root);
        f = [&]{
            vector<array<int, 2>> first(n+1);
            vector<array<int, 2>> second(n+1);
            function<void(int, int)> dfs0 = [&](int u, int p) {
                first[u] = second[u] = {0, -1};
                for (int v : adj[u]) {
                    if (v == p) {
                        continue;
                    }
                    dfs0(v, u);
                    auto fetch = first[v];
                    fetch[0] += 1;
                    fetch[1] = v;
                    if (fetch > first[u]) {
                        swap(fetch, first[u]);
                    }
                    if (fetch > second[u]) {
                        swap(fetch, second[u]);
                    }
                }
            };
            dfs0(1, 0);

            function<void(int, int)> dfs = [&](int u, int p) {
                for (int v : adj[u]) {
                    if (v == p) {
                        continue;
                    }
                    auto fetch = first[u][1] == v ? second[u] : first[u];
                    fetch[0] += 1;
                    fetch[1] = u;
                    if (fetch > first[v]) {
                        swap(fetch, first[v]);
                    }
                    if (fetch > second[v]) {
                        swap(fetch, second[v]);
                    }
                    dfs(v, u);
                }
            };
            dfs(1, 0);
            vector<int> f(n+1);
            for (int u = 1; u <= n; u++) {
                f[u] = first[u][0];
            }
            return f;
        }();
    };
    int lca(int u, int v){
        for(; head[u] != head[v]; v = pa[head[v]]){
            if(depth[head[u]] > depth[head[v]]) swap(u, v);
        }
        if(depth[u] > depth[v]) swap(u, v);
        return u;
    }
    int dist(int u, int v) {
        return depth[u]+depth[v]-2*depth[lca(u, v)];
    }
};
CentroidTree CT;
Tree TR;
vector<ll> depth, f;
void Init(int n, int A[], int B[], int D[]) {
    vector<vector<int>> adj(n+1);
    vector<vector<pair<int, int>>> adj2(n+1);
    for(int i = 0; i < n-1; i++){
        int u = A[i], v = B[i], w = D[i];
        u++; v++;
        adj[u].push_back(v);
        adj[v].push_back(u);
        adj2[u].push_back({v, w});
        adj2[v].push_back({u, w});
    }
    depth.resize(n+1, 0);
    f.resize(n+1, INF);
    auto dfs = [&](auto dfs, int u, int p) -> void{
        for(auto it : adj2[u]){
            int v = it.first, w = it.second;
            if(v == p) continue;
            depth[v] = depth[u]+w;
            dfs(dfs, v, u);
        }
    };
    dfs(dfs, 1, 0);
    CT.cons(n, adj);
    TR.cons(n, 1, adj);
}
ll dist(int u, int v){
    return depth[u]+depth[v]-depth[TR.lca(u, v)]*2;
}
long long Query(int S, int X[], int T, int Y[]) {
    ll res = INF;
    for(int i = 0; i < T; i++){
        int v = Y[i];
        v++;
        int u = v;
        while(u != 0){
            f[u] = min(f[u], dist(u, v));
            u = CT.pa[u];
        }
    }
    for(int i = 0; i < S; i++){
        int v = X[i];
        v++;
        int u = v;
        while(u != 0){
            res = min(res, f[u]+dist(u, v));
            u = CT.pa[u];
        }
    }

    for(int i = 0; i < T; i++){
        int v = Y[i];
        v++;
        int u = v;
        while(u != 0){
            f[u] = INF;
            u = CT.pa[u];
        }
    }
    return res;
}
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