Submission #735727

#	Time	Username	Problem	Language	Result	Execution time	Memory
735727		Jeff12345121	Factories (JOI14_factories)	C++14	100 / 100	6103 ms	178204 KiB

factories

#include <bits/stdc++.h>
#include "factories.h"
using namespace std;

typedef long long ll;
vector<vector<pair<int,int>>> g;
int n;
const int nmax = 500005,LOG = 21;
int sz[nmax],is_centroid[nmax],depth[nmax],cp[nmax],mput2[4 * nmax];
ll sol[nmax];
int in_reset[nmax];
long long rdis[nmax];

const ll inf = (1LL << 60);

void get_size(int node, int parent) {
    sz[node] = 1;
    for (auto k : g[node]) {
        if (k.first == parent || is_centroid[k.first]) {
            continue;
        }

        get_size(k.first, node);
        sz[node] += sz[k.first];
    }
}
int get_centroid(int node, int parent, int nr_nodes) {
    int half = nr_nodes / 2;
    for (auto k : g[node]) {
        if (k.first == parent || is_centroid[k.first]) {
            continue;
        }


        if (sz[k.first] > half) {
            return get_centroid(k.first, node, nr_nodes);
        }
    }
    return node;
}
void build_centroid(int node, int centroid_parent) {
    get_size(node, 0);
    int centroid = get_centroid(node,0, sz[node]);

    cp[centroid] = centroid_parent;
    is_centroid[centroid] = 1;
    for (auto k : g[centroid]) {
        if (is_centroid[k.first] == 0) {
            build_centroid(k.first , centroid);
        }
    }
}


vector<int> euler;
int tin[nmax],tout[nmax],cnt = 0;
void get_depth(int node, int parent) {
    for (auto k : g[node]) {
        if (k.first == parent) {
            continue;
        }

        depth[k.first] = depth[node] + 1; 
        rdis[k.first] = rdis[node] + k.second;
        get_depth(k.first, node);
    }
}
void get_euler(int node, int parent) {
    tin[node] = euler.size();
    euler.push_back(node);
    for (auto k : g[node]) {
        if (k.first == parent) {
            continue;
        }
        get_euler(k.first , node);
        euler.push_back(node);
    }
}

struct Wow {
    int node;
    bool operator < (const Wow &other) const {
        return depth[node] < depth[other.node];
    }
};
Wow rmq[LOG][4 * nmax];
void build_rmq() {
    for (int i = 1; i < euler.size(); i++) {
        rmq[0][i].node = euler[i];
    }

    mput2[1] = 0;
    for (int i = 2; i <= 2 * n; i++) {
        mput2[i] = mput2[i / 2] + 1;
    }

    for (int lvl = 1; lvl < LOG; lvl++) {
        for (int i = 1; i < (int)euler.size() - (1 << lvl) + 1; i++) {
            rmq[lvl][i] = min(rmq[lvl-1][i] , rmq[lvl - 1][i + (1 << (lvl-1))]);
        }
    }
}
int query_rmq(int l, int r) {
    if (l > r) {
        swap(l,r);
    }

    int put = mput2[r - l + 1];

    return min(rmq[put][l], rmq[put][r - (1 << put) + 1]).node;
}
int get_lca(int u, int v) {
    return query_rmq(tin[u],tin[v]);
}
void Init(int N, int A[], int B[], int D[]) {
    n = N;
    g.resize(n + 1);
    for (int i = 1; i < n; i++) {
        A[i - 1]++;
        B[i - 1]++;
        g[A[i - 1]].push_back({B[i - 1] , D[i - 1]});
        g[B[i - 1]].push_back({A[i - 1], D[i - 1]});
    }

    for (int i = 1; i <= n; i++) {
        sol[i] = inf;
    }
    
    get_depth(1,0);
    euler.push_back(-1);
    get_euler(1, 0);
    build_rmq();
    build_centroid(1, 0);
    return;
}


ll get_dis(int u, int v) {
    int lca = get_lca(u,v);
    return rdis[u] + rdis[v] - 2 * rdis[lca];
}
long long Query(int S, int X[], int T, int Y[]) {
    for (int i = 0; i < S;i++) {
        X[i]++;
    }
    for (int i = 0; i < T;i++){
        Y[i]++;
    }

    queue<int> reset_nodes;
    
    for (int i = 1; i <= S; i++) {
        for (int node = X[i - 1]; node != 0; node = cp[node]) {
            sol[node] = min(sol[node] , get_dis(node, X[i - 1]));
            if (!in_reset[node]) {
                in_reset[node] = 1;
                reset_nodes.push(node);
            }
        }
    }

    ll res = inf;
    for (int i = 1; i <= T; i++) {
        for (int node = Y[i - 1]; node != 0; node = cp[node]) {
            res = min(res, sol[node] + get_dis(node, Y[i - 1]));
        }
    }

    while(!reset_nodes.empty()) {
        in_reset[reset_nodes.front()] = 0;
        sol[reset_nodes.front()] = inf;
        reset_nodes.pop();
    }
    return res;
}

Compilation message (stderr)

factories.cpp: In function 'void build_rmq()':
factories.cpp:88:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |     for (int i = 1; i < euler.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~

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