Submission #779935

#	Time	Username	Problem	Language	Result	Execution time	Memory
779935		CDuong	Factories (JOI14_factories)	C++17	100 / 100	2214 ms	289316 KiB

factories

#include "factories.h"
#include <bits/stdc++.h>
#define taskname ""
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define ll long long
#define ld long double
#define pb push_back
#define ff first
#define ss second
#define pii pair<int, int>
#define pil pair<int, ll>
#define vi vector<int>
#define vll vector<ll>
#define vvi vector<vi>
#define vii vector<pii>
#define vil vector<pil>
#define isz(x) (int)x.size()
using namespace std;

const int mxN = 5e5 + 5;
const ll oo = 1e18;

int n;
vector<vii> G;

vi vtn;
vector<vil> vt;

ll dis[mxN];
pii sparse[20][2 * mxN];
int timer, ecnt, ap[mxN], dep[mxN], cur[mxN], tin[mxN], tout[mxN];

void dfs(int v, int p) {
    tin[v] = ++timer;
    dep[v] = dep[p] + 1;
    sparse[0][++ecnt] = {dep[v], v};
    ap[v] = ecnt;

    for(auto &[u, w] : G[v]) {
        if(u == p) continue;
        dis[u] = dis[v] + w;
        dfs(u, v);
        sparse[0][++ecnt] = {dep[v], v};
    }

    tout[v] = timer;
}

void build_sparse() {
    for(int p = 1, i = 1; p << 1 <= ecnt; p <<= 1, ++i)
        for(int j = 1; j <= ecnt - (p << 1) + 1; ++j)
            sparse[i][j] = min(sparse[i - 1][j], sparse[i - 1][j + p]);
}

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

int LCA(int u, int v) {
    int l = ap[u], r = ap[v];
    if(l > r) swap(l, r);
    int len = r - l + 1, lg_len = __lg(len);
    return min(sparse[lg_len][l], sparse[lg_len][r - (1 << lg_len) + 1]).ss;
}

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

long long Query(int S, int X[], int T, int Y[]) {
    for(int i = 0; i < S; ++i) {
        cur[X[i]] = 1;
        vtn.emplace_back(X[i]);
    }
    for(int i = 0; i < T; ++i) {
        cur[Y[i]] = 2;
        vtn.emplace_back(Y[i]);
    }

    sort(all(vtn), [&](int u, int v) {
        return tin[u] < tin[v];
    });

    for(int i = 0; i < S + T - 1; ++i) {
        vtn.emplace_back(LCA(vtn[i], vtn[i + 1]));
    }

    sort(all(vtn), [&](int u, int v) {
        return tin[u] < tin[v];
    });
    vtn.erase(unique(all(vtn)), vtn.end());

    auto add_vt = [&](int u, int v, ll w) {
        vt[u].emplace_back(v, w);
        vt[v].emplace_back(u, w);
    };

    stack<int> s;
    for(int i = 0; i < isz(vtn); ++i) {
        while(not s.empty() && not is_ancestor(s.top(), vtn[i])) s.pop();
        if(s.empty()) s.emplace(vtn[i]);
        else {
            add_vt(s.top(), vtn[i], dis[vtn[i]] - dis[s.top()]);
            s.emplace(vtn[i]);
        }
    }

    ll res = oo;

    auto dfs = [&](auto self, int v, int p) -> vll {
        vll cur_dis(2, oo);
        if(cur[v]) cur_dis[cur[v] - 1] = 0;
        for(auto &[u, w] : vt[v]) {
            if(u == p) continue;
            vll tmp = self(self, u, v);
            for(int i = 0; i < 2; ++i)
                cur_dis[i] = min(cur_dis[i], tmp[i] + w);
        }
        res = min(res, cur_dis[0] + cur_dis[1]);
        return cur_dis;
    };

    dfs(dfs, vtn[0], 0);

    while(not vtn.empty()) {
        cur[vtn.back()] = 0;
        vt[vtn.back()].clear();
        vtn.pop_back();
    }

    return res;
}

• Subtask 1: 15 / 15
• Subtask 2: 18 / 18
• Subtask 3: 67 / 67