Submission #553273

#	Time	Username	Problem	Language	Result	Execution time	Memory
553273		RaresFelix	Collapse (JOI18_collapse)	C++17	0 / 100	34 ms	3604 KiB

collapse

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

using namespace std;
using Edge = tuple<int, int, int, int>; //from, to, begin, end
using vEd = vector<Edge>;
using vi = vector<int>;

struct DSU { /// with roll_back
    int n;
    vector<int> P, S;
    DSU(int n) : n(n) {
        P.resize(n), S.assign(n, 1);
        for(int i = 0; i < n; ++i) P[i] = i;
    }
    int repr(int u) {
        return u == P[u] ? u : repr(P[u]);
    }
    int nr_uni = 0;
    stack<int> RP, RS;
    void uni(int u, int v) {
        u = repr(u), v = repr(v);
        if(u == v) return;
        if(S[u] < S[v]) swap(u, v);
        ++nr_uni, RP.push(v); RS.push(S[v]);
        P[v] = u, S[u] += S[v];
    }
    void roll_back(int update_count) {
        while(nr_uni > update_count) {
            --nr_uni;
            P[RP.top()] = RP.top();
            S[RP.top()] = RS.top();
            RP.pop(), RS.pop();
        }
    }
};

struct Bucket {
    DSU Simu;
    int begin, end;
    Bucket(int n, int begin, int end) : Simu(n), begin(begin), end(end) {}
    vector<Edge> idk;
    void add_edge(Edge nou) {
        auto &[f, t, b, e] = nou;
        if(e < begin || end < b) return;
        if(b <= begin && end <= e) { //complet
            Simu.uni(f, t);
            return;
        }
        idk.push_back(nou);
    }
    int query(int timp) {
        int count0 = Simu.nr_uni;
        for(auto &it : idk) {
            auto &[f, t, b, e] = it;
            if(b <= timp && timp <= e) Simu.uni(f, t);
        }
        int re = Simu.nr_uni;
        Simu.roll_back(count0);
        return re;
    }
};

void solve(int n, int c, int q, vEd &edges, vi &W, vi &P, vi &R) {
    R.assign(q, 0);
    vector<vi> Queries(c + 1);
    for(int i = 0; i < q; ++i)
        Queries[P[i]].push_back(i);
    vector<vEd> Add(n + 1);
    for(auto &[f, t, b, e] : edges)
        Add[t].push_back({f, t, b, e});

    int bucketSize = int(sqrt(c + 1));
    vector<Bucket> Sol;
    for(int lp = 0; lp <= c + 1; lp += bucketSize)
        Sol.emplace_back(n, lp, lp + bucketSize - 1);

    for(int i = 0; i < n; ++i) {
        for(auto &it : Add[i])
            for(auto &seg : Sol) seg.add_edge(it);
        for(auto &qid : Queries[i]) {
            int w = W[qid];
            int re = 0;
            for(auto &seg : Sol) {
                if(seg.begin <= w && w <= seg.end) {
                    re = seg.query(w);
                    break;
                }
            }
            R[qid] = i + 1 - re;
        }
    }
}

vector<int> simulateCollapse(
	int n,
	vector<int> T,
	vector<int> X,
	vector<int> Y,
	vector<int> W,
	vector<int> P
) {
    vEd edges;
    int c = T.size(), q = W.size();
    map<pair<int, int>, int> enabled;
    for(int i = 0 ; i < c; ++i)
        if(X[i] > Y[i]) swap(X[i], Y[i]);
    for(int i = 0 ; i < c; ++i) {
        if(!T[i])
            enabled[{X[i], Y[i]}] = i;
        else {
            edges.push_back({X[i], Y[i], enabled[{X[i], Y[i]}], c});
            enabled[{X[i], Y[i]}] = -1;
        }
    }
    for(auto [p, e] : enabled) if(e != -1) {
        auto [f, t] = p;
        edges.push_back({f, t, e, c + 1});
    }
    vector<int> R, R1, R2;
    solve(n, c, q, edges, W, P, R1);
    for(auto &it : P) it = n - 1 - it;
    for(auto &[a, b, c, d] : edges)
        a = n - 1 - a, b = n - 1 - b, a ^= b, b ^= a, a ^= b;
    solve(n, c, q, edges, W, P, R2);
    for(int i = 0; i < q; ++i) R.push_back(R1[i] + R2[i]);
    return R;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 30
• Subtask 3: 0 / 30
• Subtask 4: 0 / 35