Submission #908195

#	Time	Username	Problem	Language	Result	Execution time	Memory
908195		typ_ik	Factories (JOI14_factories)	C++17	100 / 100	5644 ms	369212 KiB

factories

#include <bits/stdc++.h>
#include "factories.h"

#define ll long long
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define watch(x) cout << (#x) << " : " << x << '\n'
#define boost ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

using namespace std; 

const int N = 5e5 + 128;
const ll INF = 1e15 + 128; 
vector < pair<int, int> > g[N];
int n, q;
bool was[N];
int h[N]; 
ll res[N];   

void dfs(int v, int p = -1) {
    h[v] = 1;    

    for (auto& [to, len] : g[v])
        if (to != p && !was[to])
            dfs(to, v), h[v] += h[to];
}  

vector < pair<int, ll> > p[N];

void calc(int v, int cent, ll val, int pr = -1) {
    p[v].push_back(make_pair(cent, val));

    for (auto& [to, len] : g[v])
        if (to != pr && !was[to])
            calc(to, cent, val+len, v);
} 

int find_centroid(int v, int pr, int sz) { 
    for (auto& [to, len] : g[v])
        if (to != pr && h[to] > sz / 2 && !was[to])
            return find_centroid(to, v, sz);
    return v;
} 

void decompose(int v, int pr = -1) { 
    dfs(v); 

    int c = find_centroid(v, -1, h[v]);    

    calc(c, c, 0);
    was[c] = true;

    for (auto& [to, len] : g[c])
        if (!was[to])
            decompose(to, c);
}

void update(int v) {
    for (auto& [x, d] : p[v])
        res[x] = min(res[x], d); 
}

void reset(int v) {
    for (auto& [x, d] : p[v])
        res[x] = INF; 
}

ll get(int v) {
    ll ans = INF;
    for (auto& [x, d] : p[v])
        ans = min(ans, d + res[x]); 
    return ans;
}

void Init(int N, int A[], int B[], int D[]) {
    n = N;
    for (int i = 0; i + 1 < n; i++) {
        int u = A[i], v = B[i], w = D[i];
        g[u].push_back(make_pair(v, w));
        g[v].push_back(make_pair(u, w));
    }
    for (int i = 0; i <= n; i++)
        res[i] = INF;
    decompose(1); 
}

long long Query(int S, int X[], int T, int Y[]) {
    for (int i = 0; i < S; i++)
        update(X[i]);
    ll tot = INF;
    for (int i = 0; i < T; i++)
        tot = min(tot, get(Y[i]));
    for (int i = 0; i < S; i++)
        reset(X[i]);
    return tot;
}   

// main() {
//     boost;
//     int A[] = {0, 1, 2, 2, 4, 1};
//     int B[] = {1, 2, 3, 4, 5, 6};
//     int D[] = {4, 4, 5, 6, 5, 3};
//     Init(7, A, B, D);
//     int X[] = {0, 6};
//     int Y[] = {3, 4};
//     cout << Query(2, X, 2, Y) << '\n';
//     return 0;
// }

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