제출 #587245

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
587245		danikoynov	공장들 (JOI14_factories)	C++14	100 / 100	4674 ms	297760 KiB

factories

#include <bits/stdc++.h>
#include "factories.h"
using namespace std;
typedef long long ll;
const int maxn = 5e5 + 10;
const ll inf = 1e18;

vector < pair < int, ll > > g[maxn];
int n, root, sub[maxn], used[maxn], par[maxn];
int f[2 * maxn], in[maxn], timer;
ll depth[maxn], cl[maxn];
void calc(int v, int p, bool st)
{
    if (st)
    {
        f[++ timer] = v;
        in[v] = timer;
    }
    sub[v] = 1;
    for (pair < int, ll > nb : g[v])
    {
        int u = nb.first;
        if (u == p || used[u])
            continue;
        if (st)
            depth[u] = depth[v] + nb.second;
        calc(u, v, st);
        sub[v] += sub[u];
        if (st)
            f[++ timer] = v;
    }
}

const int maxlog = 21;
ll dp[maxn * 2][maxlog], lg[maxn * 2];

void build_sparse_table()
{
    /**for (int i = 1; i <= timer; i ++)
        cout << f[i] << " ";
    cout << endl;*/
    for (int i = 1; i <= timer; i ++)
        dp[i][0] = depth[f[i]], lg[i] = lg[i / 2] + 1;

    for (int j = 1; j < lg[timer]; j ++)
        for (int i = 1; i <= timer - (1 << j) + 1; i ++)
        {
            dp[i][j] = dp[i][j - 1];
            if (dp[i + (1 << (j - 1))][j - 1] < dp[i][j])
                dp[i][j] = dp[i + (1 << (j - 1))][j - 1];
        }

}

ll dist(int v, int u)
{
    int l = in[v], r = in[u];
    if (l > r)
        swap(l, r);

    int len = lg[r - l + 1] - 1;
    return depth[v] + depth[u] - 2 * min(dp[l][len], dp[r - (1 << len) + 1][len]);
}

int decompose(int v, int p, int sz)
{
    for (pair < int, ll > nb : g[v])
    {
        int u = nb.first;
        if (u == p || used[u])
            continue;
        if (sub[u] > sz / 2)
            return decompose(u, v, sz);
    }

    /// v is centroid
    used[v] = 1;

    for (pair < int, ll > nb : g[v])
    {
        int u = nb.first;
        if (used[u])
            continue;
        if (u == p)
            calc(u, v, 0);
        par[decompose(u, v, sub[u])] = v;
    }

    return v;
}
void Init(int N, int A[], int B[], int D[])
{
    n = N;
    for (int i = 0; i < n - 1; i ++)
    {
        g[A[i]].push_back({B[i], (ll)D[i]});
        g[B[i]].push_back({A[i], (ll)D[i]});
    }

    calc(0, -1, 1);
    root = decompose(0, -1, n);
    build_sparse_table();
    par[root] = -1;

    for (int i = 0; i < n; i ++)
        cl[i] = inf;
    ///cout << dist(2, 5) << endl;
}


ll Query(int S, int X[], int T, int Y[])
{
    ll ans = inf;
    for (int i = 0; i < S; i ++)
    {
        int v = X[i];
        while(v != par[root])
        {
            cl[v] = min(cl[v], dist(v, X[i]));
            v = par[v];
        }
    }

    for (int i = 0; i < T; i ++)
    {
        int u = Y[i];
        while(u != par[root])
        {
            ans = min(ans, cl[u] + dist(u, Y[i]));
            u = par[u];
        }
    }

    for (int i = 0; i < S; i ++)
    {
        int v = X[i];
        while(v != par[root])
        {
            cl[v] = inf;
            v = par[v];
        }
    }
    return ans;

}

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